diff --git a/addons/isl-server/proxy/existingServerStateFiles.ts b/addons/isl-server/proxy/existingServerStateFiles.ts
index 860e5a31b77ec..d01f59780e8e2 100644
--- a/addons/isl-server/proxy/existingServerStateFiles.ts
+++ b/addons/isl-server/proxy/existingServerStateFiles.ts
@@ -9,7 +9,7 @@ import rmtree from './rmtree';
 import fs from 'fs';
 import os from 'os';
 import path from 'path';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 export type ExistingServerInfo = {
   sensitiveToken: string;
@@ -28,7 +28,7 @@ export type ExistingServerInfo = {
 
 const cacheDir =
   process.platform == 'win32'
-    ? path.join(unwrap(process.env.LOCALAPPDATA), 'cache')
+    ? path.join(nullthrows(process.env.LOCALAPPDATA), 'cache')
     : process.platform == 'darwin'
     ? path.join(os.homedir(), 'Library/Caches')
     : process.env.XDG_CACHE_HOME || path.join(os.homedir(), '.cache');
diff --git a/addons/isl-server/src/Repository.ts b/addons/isl-server/src/Repository.ts
index ab2feb443d95f..6b2ddd1699064 100644
--- a/addons/isl-server/src/Repository.ts
+++ b/addons/isl-server/src/Repository.ts
@@ -85,7 +85,7 @@ import {RateLimiter} from 'shared/RateLimiter';
 import {TypedEventEmitter} from 'shared/TypedEventEmitter';
 import {exists} from 'shared/fs';
 import {removeLeadingPathSep} from 'shared/pathUtils';
-import {notEmpty, randomId, unwrap} from 'shared/utils';
+import {notEmpty, randomId, nullthrows} from 'shared/utils';
 
 /**
  * This class is responsible for providing information about the working copy
@@ -497,7 +497,7 @@ export class Repository {
   }
 
   private normalizeOperationArgs(cwd: string, args: Array<CommandArg>): Array<string> {
-    const repoRoot = unwrap(this.info.repoRoot);
+    const repoRoot = nullthrows(this.info.repoRoot);
     return args.flatMap(arg => {
       if (typeof arg === 'object') {
         switch (arg.type) {
diff --git a/addons/isl-server/src/ServerToClientAPI.ts b/addons/isl-server/src/ServerToClientAPI.ts
index e964856d040b4..66ff83e507d9b 100644
--- a/addons/isl-server/src/ServerToClientAPI.ts
+++ b/addons/isl-server/src/ServerToClientAPI.ts
@@ -36,7 +36,7 @@ import {repositoryCache} from './RepositoryCache';
 import {findPublicAncestor, parseExecJson} from './utils';
 import {serializeToString, deserializeFromString} from 'isl/src/serialize';
 import {revsetForComparison} from 'shared/Comparison';
-import {randomId, unwrap} from 'shared/utils';
+import {randomId, nullthrows} from 'shared/utils';
 import {Readable} from 'stream';
 
 export type IncomingMessage = ClientToServerMessage;
@@ -254,7 +254,7 @@ export default class ServerToClientAPI {
         }
         this.tracker
           .operation('UploadImage', 'UploadImageError', {}, () =>
-            uploadFile(unwrap(this.connection.logger), {filename, data: payload}),
+            uploadFile(nullthrows(this.connection.logger), {filename, data: payload}),
           )
           .then((result: string) => {
             this.connection.logger?.info('sucessfully uploaded file', filename, result);
diff --git a/addons/isl-server/src/analytics/environment.ts b/addons/isl-server/src/analytics/environment.ts
index d5628b5be8f7d..adda678bf0257 100644
--- a/addons/isl-server/src/analytics/environment.ts
+++ b/addons/isl-server/src/analytics/environment.ts
@@ -8,7 +8,7 @@
 import type {ApplicationInfo} from './types';
 
 import os from 'os';
-import {randomId, unwrap} from 'shared/utils';
+import {randomId, nullthrows} from 'shared/utils';
 
 export function getUsername(): string {
   try {
@@ -16,7 +16,7 @@ export function getUsername(): string {
   } catch (osInfoError) {
     try {
       const {env} = process;
-      return unwrap(env.LOGNAME || env.USER || env.LNAME || env.USERNAME);
+      return nullthrows(env.LOGNAME || env.USER || env.LNAME || env.USERNAME);
     } catch (processEnvError) {
       throw new Error(String(processEnvError) + String(osInfoError));
     }
diff --git a/addons/isl-server/src/serverPlatform.ts b/addons/isl-server/src/serverPlatform.ts
index 3b41d09db35aa..359afea648238 100644
--- a/addons/isl-server/src/serverPlatform.ts
+++ b/addons/isl-server/src/serverPlatform.ts
@@ -15,7 +15,7 @@ import type {
 
 import {spawn} from 'child_process';
 import pathModule from 'path';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 /**
  * Platform-specific server-side API for each target: vscode extension host, electron standalone, browser, ...
@@ -43,7 +43,10 @@ export const browserServerPlatform: ServerPlatform = {
   ) => {
     switch (message.type) {
       case 'platform/openContainingFolder': {
-        const absPath: AbsolutePath = pathModule.join(unwrap(repo?.info.repoRoot), message.path);
+        const absPath: AbsolutePath = pathModule.join(
+          nullthrows(repo?.info.repoRoot),
+          message.path,
+        );
         let args: Array<string> = [];
         // use OS-builtin open command to open parent directory
         // (which may open different file extensions with different programs)
diff --git a/addons/isl/src/Cleanup.tsx b/addons/isl/src/Cleanup.tsx
index c30c7145bbffb..bd6a75fedc58a 100644
--- a/addons/isl/src/Cleanup.tsx
+++ b/addons/isl/src/Cleanup.tsx
@@ -19,7 +19,7 @@ import {type Dag, dagWithPreviews} from './previews';
 import {VSCodeButton} from '@vscode/webview-ui-toolkit/react';
 import {useAtomValue} from 'jotai';
 import {Icon} from 'shared/Icon';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 export function isStackEligibleForCleanup(
   hash: Hash,
@@ -99,7 +99,7 @@ export function CleanupAllButton() {
         contextKey="cleanup-all"
         runOperation={() => {
           return cleanableStacks.map(hash => {
-            const info = unwrap(dag.get(hash));
+            const info = nullthrows(dag.get(hash));
             return new HideOperation(latestSuccessorUnlessExplicitlyObsolete(info));
           });
         }}
diff --git a/addons/isl/src/CommitInfoView/CommitInfoView.tsx b/addons/isl/src/CommitInfoView/CommitInfoView.tsx
index d58428a24f2d3..94fe80735473e 100644
--- a/addons/isl/src/CommitInfoView/CommitInfoView.tsx
+++ b/addons/isl/src/CommitInfoView/CommitInfoView.tsx
@@ -87,7 +87,7 @@ import {useCallback, useEffect} from 'react';
 import {ComparisonType} from 'shared/Comparison';
 import {useContextMenu} from 'shared/ContextMenu';
 import {Icon} from 'shared/Icon';
-import {firstLine, notEmpty, unwrap} from 'shared/utils';
+import {firstLine, notEmpty, nullthrows} from 'shared/utils';
 
 import './CommitInfoView.css';
 
@@ -779,7 +779,7 @@ function ActionsBar({
                     answer,
                   );
                   setRepoInfo(info => ({
-                    ...unwrap(info),
+                    ...nullthrows(info),
                     preferredSubmitCommand: answer,
                   }));
                   // setRepoInfo updates `provider`, but we still have a stale reference in this callback.
@@ -802,7 +802,7 @@ function ActionsBar({
                 // during another amend or amend message.
                 const shouldUpdateMessage = !isCommitMode && messageSyncEnabled && anythingToCommit;
 
-                const submitOp = unwrap(provider).submitOperation(
+                const submitOp = nullthrows(provider).submitOperation(
                   commit.isHead ? [] : [commit], // [] means to submit the head commit
                   {
                     draft: shouldSubmitAsDraft,
diff --git a/addons/isl/src/CommitInfoView/GenerateWithAI.tsx b/addons/isl/src/CommitInfoView/GenerateWithAI.tsx
index 6d28a450c6593..98dca7c949c67 100644
--- a/addons/isl/src/CommitInfoView/GenerateWithAI.tsx
+++ b/addons/isl/src/CommitInfoView/GenerateWithAI.tsx
@@ -30,7 +30,7 @@ import {useCallback} from 'react';
 import {ComparisonType} from 'shared/Comparison';
 import {Icon} from 'shared/Icon';
 import {useThrottledEffect} from 'shared/hooks';
-import {randomId, unwrap} from 'shared/utils';
+import {randomId, nullthrows} from 'shared/utils';
 
 import './GenerateWithAI.css';
 
@@ -145,7 +145,7 @@ const generatedCommitMessages = atomFamilyWeak((hashKey: string | undefined) =>
         const comparison: Comparison = hashKey.startsWith('commit/')
           ? {type: ComparisonType.UncommittedChanges}
           : {type: ComparisonType.Committed, hash: hashKey};
-        const response = await unwrap(Internal.generateAICommitMessage)({
+        const response = await nullthrows(Internal.generateAICommitMessage)({
           comparison,
           title: latestWrittenTitle,
         });
@@ -296,7 +296,7 @@ class FunnelTracker {
   /** Get or create the funnel tracker for this hashKey */
   static get(hashKey: HashKey): FunnelTracker {
     if (this.trackersByHashKey.has(hashKey)) {
-      return unwrap(this.trackersByHashKey.get(hashKey));
+      return nullthrows(this.trackersByHashKey.get(hashKey));
     }
     const tracker = new FunnelTracker();
     this.trackersByHashKey.set(hashKey, tracker);
diff --git a/addons/isl/src/ComparisonView/SplitDiffView/syntaxHighlighting.tsx b/addons/isl/src/ComparisonView/SplitDiffView/syntaxHighlighting.tsx
index afd1b59e4c463..66c2199a8e752 100644
--- a/addons/isl/src/ComparisonView/SplitDiffView/syntaxHighlighting.tsx
+++ b/addons/isl/src/ComparisonView/SplitDiffView/syntaxHighlighting.tsx
@@ -22,7 +22,7 @@ import FilepathClassifier from 'shared/textmate-lib/FilepathClassifier';
 import createTextMateRegistry from 'shared/textmate-lib/createTextMateRegistry';
 import {updateTextMateGrammarCSS} from 'shared/textmate-lib/textmateStyles';
 import {tokenizeLines} from 'shared/textmate-lib/tokenize';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 import {loadWASM} from 'vscode-oniguruma';
 
 const URL_TO_ONIG_WASM = 'generated/textmate/onig.wasm';
@@ -208,7 +208,7 @@ async function tokenizeContent(
 const grammarCache: Map<string, Promise<IGrammar | null>> = new Map();
 function getGrammar(store: Registry, scopeName: string): Promise<IGrammar | null> {
   if (grammarCache.has(scopeName)) {
-    return unwrap(grammarCache.get(scopeName));
+    return nullthrows(grammarCache.get(scopeName));
   }
   const grammarPromise = store.loadGrammar(scopeName);
   grammarCache.set(scopeName, grammarPromise);
diff --git a/addons/isl/src/ConfirmSubmitStack.tsx b/addons/isl/src/ConfirmSubmitStack.tsx
index e03f17c945e20..7f213e3db3f85 100644
--- a/addons/isl/src/ConfirmSubmitStack.tsx
+++ b/addons/isl/src/ConfirmSubmitStack.tsx
@@ -22,7 +22,7 @@ import {VSCodeDivider, VSCodeButton, VSCodeTextField} from '@vscode/webview-ui-t
 import {useAtom, useAtomValue} from 'jotai';
 import {useState} from 'react';
 import {useAutofocusRef} from 'shared/hooks';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 import './ConfirmSubmitStack.css';
 
@@ -66,7 +66,10 @@ export function useShowConfirmSubmitStack() {
 
     const provider = readAtom(codeReviewProvider);
 
-    const replace = {$numCommits: String(stack.length), $cmd: unwrap(provider).submitCommandName()};
+    const replace = {
+      $numCommits: String(stack.length),
+      $cmd: nullthrows(provider).submitCommandName(),
+    };
     const title =
       mode === 'submit'
         ? t('Submitting $numCommits commits for review with $cmd', {replace})
diff --git a/addons/isl/src/DownloadCommitsMenu.tsx b/addons/isl/src/DownloadCommitsMenu.tsx
index 0c981341a076c..9493fa18289fd 100644
--- a/addons/isl/src/DownloadCommitsMenu.tsx
+++ b/addons/isl/src/DownloadCommitsMenu.tsx
@@ -29,7 +29,7 @@ import {useAtom} from 'jotai';
 import {useEffect, useRef, useState} from 'react';
 import {Icon} from 'shared/Icon';
 import {KeyCode, Modifier} from 'shared/KeyboardShortcuts';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 import './DownloadCommitsMenu.css';
 
@@ -128,7 +128,7 @@ function DownloadCommitsTooltip({dismiss}: {dismiss: () => unknown}) {
       const dest =
         rebaseType === 'rebase_ontop'
           ? '.'
-          : unwrap(findCurrentPublicBase(readAtom(dagWithPreviews))?.hash);
+          : nullthrows(findCurrentPublicBase(readAtom(dagWithPreviews))?.hash);
       // Use exact revsets for sources, so that you can type a specific hash to download and not be surprised by succession.
       // Only use succession for destination, which may be in flux at the moment you start the download.
       runOperation(new Op(exactRevset(enteredDiffNum), succeedableRevset(dest)));
diff --git a/addons/isl/src/SettingsTooltip.tsx b/addons/isl/src/SettingsTooltip.tsx
index 8f14cb166b2fb..7fdc05c9202ae 100644
--- a/addons/isl/src/SettingsTooltip.tsx
+++ b/addons/isl/src/SettingsTooltip.tsx
@@ -39,7 +39,7 @@ import {
 import {useAtom, useAtomValue} from 'jotai';
 import {Icon} from 'shared/Icon';
 import {KeyCode, Modifier} from 'shared/KeyboardShortcuts';
-import {tryJsonParse, unwrap} from 'shared/utils';
+import {tryJsonParse, nullthrows} from 'shared/utils';
 
 import './VSCodeDropdown.css';
 import './SettingsTooltip.css';
@@ -159,7 +159,7 @@ function SettingsDropdown({
               runOperation(
                 new SetConfigOperation('local', 'github.preferred_submit_command', value),
               );
-              setRepoInfo(info => ({...unwrap(info), preferredSubmitCommand: value}));
+              setRepoInfo(info => ({...nullthrows(info), preferredSubmitCommand: value}));
             }}>
             {repoInfo.preferredSubmitCommand == null ? (
               <VSCodeOption value={'not set'}>(not set)</VSCodeOption>
diff --git a/addons/isl/src/__tests__/ComparisonView.test.tsx b/addons/isl/src/__tests__/ComparisonView.test.tsx
index 048c8f66b3cd4..34cabbbe1bf2b 100644
--- a/addons/isl/src/__tests__/ComparisonView.test.tsx
+++ b/addons/isl/src/__tests__/ComparisonView.test.tsx
@@ -26,7 +26,7 @@ import fs from 'fs';
 import path from 'path';
 import {ComparisonType} from 'shared/Comparison';
 import {nextTick} from 'shared/testUtils';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 afterEach(cleanup);
 
@@ -594,7 +594,7 @@ function mockFetchToSupportSyntaxHighlighting(): jest.SpyInstance {
     jest.fn(async url => {
       if (url.includes('generated/textmate')) {
         const match = /.*generated\/textmate\/(.*)$/.exec(url);
-        const filename = unwrap(match)[1];
+        const filename = nullthrows(match)[1];
         const toPublicDir = (filename: string) =>
           path.normalize(path.join(__dirname, '../../public/generated/textmate', filename));
         if (filename === 'onig.wasm') {
diff --git a/addons/isl/src/__tests__/FillCommitMessage.test.tsx b/addons/isl/src/__tests__/FillCommitMessage.test.tsx
index e958108769199..c84d214fab1c8 100644
--- a/addons/isl/src/__tests__/FillCommitMessage.test.tsx
+++ b/addons/isl/src/__tests__/FillCommitMessage.test.tsx
@@ -18,7 +18,7 @@ import {
 import {fireEvent, render, screen, waitFor, within} from '@testing-library/react';
 import userEvent from '@testing-library/user-event';
 import {act} from 'react-dom/test-utils';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 /* eslint-disable @typescript-eslint/no-non-null-assertion */
 
@@ -110,7 +110,7 @@ describe('FillCommitMessage', () => {
     expect(loadFromLastCommit).toBeInTheDocument();
     fireEvent.click(loadFromLastCommit);
     await waitFor(() => expect(getTitleEditor().value).toMatch('Head Commit'));
-    expect(getFieldEditor(unwrap(Internal.diffFieldTag))).toHaveValue('');
+    expect(getFieldEditor(nullthrows(Internal.diffFieldTag))).toHaveValue('');
   });
 
   it('Load from commit template', async () => {
diff --git a/addons/isl/src/__tests__/Shelve.test.tsx b/addons/isl/src/__tests__/Shelve.test.tsx
index 8160d65354c8c..974603bd7459d 100644
--- a/addons/isl/src/__tests__/Shelve.test.tsx
+++ b/addons/isl/src/__tests__/Shelve.test.tsx
@@ -21,7 +21,7 @@ import {fireEvent, render, screen, waitFor, within} from '@testing-library/react
 import userEvent from '@testing-library/user-event';
 import {act} from 'react-dom/test-utils';
 import {ComparisonType} from 'shared/Comparison';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 describe('Shelve', () => {
   beforeEach(() => {
@@ -99,7 +99,7 @@ describe('Shelve', () => {
 
       // uncheck one file
       fireEvent.click(
-        unwrap(
+        nullthrows(
           screen.getByTestId('changed-file-src/file2.js').querySelector('input[type=checkbox]'),
         ),
       );
diff --git a/addons/isl/src/codeReview/CodeReviewInfo.ts b/addons/isl/src/codeReview/CodeReviewInfo.ts
index c49fc7e07a555..9d6537eea88cb 100644
--- a/addons/isl/src/codeReview/CodeReviewInfo.ts
+++ b/addons/isl/src/codeReview/CodeReviewInfo.ts
@@ -27,7 +27,7 @@ import {GithubUICodeReviewProvider} from './github/github';
 import {atom} from 'jotai';
 import {clearTrackedCache} from 'shared/LRU';
 import {debounce} from 'shared/debounce';
-import {firstLine, unwrap} from 'shared/utils';
+import {firstLine, nullthrows} from 'shared/utils';
 
 export const codeReviewProvider = atom<UICodeReviewProvider | null>(get => {
   const repoInfo = get(repositoryInfo);
@@ -88,7 +88,10 @@ registerDisposable(
 
       // merge old values with newly fetched ones
       return {
-        value: new Map([...unwrap(existing.value).entries(), ...event.summaries.value.entries()]),
+        value: new Map([
+          ...nullthrows(existing.value).entries(),
+          ...event.summaries.value.entries(),
+        ]),
       };
     });
   }),
diff --git a/addons/isl/src/dag/base_dag.ts b/addons/isl/src/dag/base_dag.ts
index 3094eab00e68e..54bdfd26c2f2d 100644
--- a/addons/isl/src/dag/base_dag.ts
+++ b/addons/isl/src/dag/base_dag.ts
@@ -13,7 +13,7 @@ import {HashSet} from './set';
 import {Map as ImMap, Record, List} from 'immutable';
 import {LRU, cachedMethod} from 'shared/LRU';
 import {SelfUpdate} from 'shared/immutableExt';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 /**
  * Hash-map like container with graph related queries.
@@ -263,7 +263,8 @@ export class BaseDag<C extends HashWithParents> extends SelfUpdate<BaseDagRecord
     const filledSet = gap ? this.range(hashSet, hashSet) : hashSet;
     const alreadyVisited = new Set<Hash>();
     // We use concat and pop (not unshift) so the order is reversed.
-    const compareHash = (a: Hash, b: Hash) => -compare(unwrap(this.get(a)), unwrap(this.get(b)));
+    const compareHash = (a: Hash, b: Hash) =>
+      -compare(nullthrows(this.get(a)), nullthrows(this.get(b)));
     // The number of parents remaining to be visited. This ensures merges are not
     // outputted until all parents are outputted.
     const remaining = new Map<Hash, number>(
diff --git a/addons/isl/src/dag/dag.ts b/addons/isl/src/dag/dag.ts
index 2e3d35ea7aee5..d2d45c23beef0 100644
--- a/addons/isl/src/dag/dag.ts
+++ b/addons/isl/src/dag/dag.ts
@@ -20,7 +20,7 @@ import {arrayFromHashes, HashSet} from './set';
 import {List, Record, Map as ImMap, Set as ImSet} from 'immutable';
 import {LRU, cachedMethod} from 'shared/LRU';
 import {SelfUpdate} from 'shared/immutableExt';
-import {group, notEmpty, splitOnce, unwrap} from 'shared/utils';
+import {group, notEmpty, splitOnce, nullthrows} from 'shared/utils';
 
 /**
  * Main commit graph type used for preview calculation and queries.
@@ -369,7 +369,7 @@ export class Dag extends SelfUpdate<CommitDagRecord> {
       const pureHash = isSucc ? h.substring(REBASE_SUCC_PREFIX.length) : h;
       const isPred = !isSucc && duplicated.contains(h);
       const isRoot = srcRoots.contains(pureHash);
-      const info = unwrap(isSucc ? this.get(pureHash) : c);
+      const info = nullthrows(isSucc ? this.get(pureHash) : c);
       return info.withMutations(mut => {
         // Reset the seqNumber so the rebase preview tends to show as right-most branches.
         let newInfo = mut.set('seqNumber', undefined);
@@ -565,7 +565,7 @@ export class Dag extends SelfUpdate<CommitDagRecord> {
     // Render row by row. The main complexity is to figure out the "ancestors",
     // especially when the provided `set` is a subset of the dag.
     for (const hash of sorted) {
-      const info = unwrap(this.get(hash));
+      const info = nullthrows(this.get(hash));
       const parents: ReadonlyArray<Hash> = info?.parents ?? [];
       // directParents: solid edges
       // indirectParents: dashed edges
diff --git a/addons/isl/src/linelog.ts b/addons/isl/src/linelog.ts
index 73af4f32cd83a..c5bdeeb17f615 100644
--- a/addons/isl/src/linelog.ts
+++ b/addons/isl/src/linelog.ts
@@ -37,7 +37,7 @@ import {hash, List, Record, Set as ImSet} from 'immutable';
 import {cached, cachedMethod, LRU} from 'shared/LRU';
 import {diffLines, splitLines} from 'shared/diff';
 import {SelfUpdate} from 'shared/immutableExt';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 /** Operation code. */
 enum Op {
@@ -378,7 +378,7 @@ class Code implements ValueObject {
       if (aLinesMutable) {
         aLines[a1] = {...aLines[a1], pc: jlInst == null ? code.size : code.size + 1};
       }
-      const a1Inst = unwrap(code.get(a1Pc));
+      const a1Inst = nullthrows(code.get(a1Pc));
       if (jlInst === undefined) {
         // [3]
         code = code.push(a1Inst);
@@ -551,7 +551,7 @@ class Code implements ValueObject {
         delStack.pop();
         onStackPop?.(delStack);
       }
-      const code = unwrap(this.get(pc));
+      const code = nullthrows(this.get(pc));
       switch (code.op) {
         case Op.LINE:
           onLine?.(code);
@@ -898,7 +898,7 @@ class LineLog extends SelfUpdate<LineLogRecord> {
     let patience = this.code.getSize() * 2;
     const deleted = present == null ? () => false : (pc: Pc) => !present[pc];
     while (patience > 0) {
-      const code = unwrap(this.code.get(pc));
+      const code = nullthrows(this.code.get(pc));
       switch (code.op) {
         case Op.END:
           lines.push({data: '', rev: 0, pc, deleted: deleted(pc)});
diff --git a/addons/isl/src/platform/__tests__/webviewPlatform.test.ts b/addons/isl/src/platform/__tests__/webviewPlatform.test.ts
index 301ac17c0280a..86579e1e13360 100644
--- a/addons/isl/src/platform/__tests__/webviewPlatform.test.ts
+++ b/addons/isl/src/platform/__tests__/webviewPlatform.test.ts
@@ -6,7 +6,7 @@
  */
 
 import {webviewPlatform} from '../webviewPlatform';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 (window.external as unknown as Record<string, unknown>).invoke = jest.fn();
 
@@ -39,7 +39,7 @@ describe('webview platform', () => {
       id: 1,
     });
 
-    const result = unwrap(await promise);
+    const result = nullthrows(await promise);
     expect(result[0].name).toEqual('file.txt');
     expect(await result[0].size).toEqual(5);
   });
diff --git a/addons/isl/src/previews.ts b/addons/isl/src/previews.ts
index 18992ada148c5..acff8411b0fc5 100644
--- a/addons/isl/src/previews.ts
+++ b/addons/isl/src/previews.ts
@@ -27,7 +27,7 @@ import {
 } from './serverAPIState';
 import {atom, useAtom, useAtomValue} from 'jotai';
 import {useEffect} from 'react';
-import {notEmpty, unwrap} from 'shared/utils';
+import {notEmpty, nullthrows} from 'shared/utils';
 
 export enum CommitPreview {
   REBASE_ROOT = 'rebase-root',
@@ -402,7 +402,7 @@ export function useMarkOperationsCompleted(): void {
             if (optimisticApplier == null || operation.exitCode !== 0) {
               files = true;
             } else if (
-              uncommittedChanges.fetchStartTimestamp > unwrap(operation.endTime).valueOf()
+              uncommittedChanges.fetchStartTimestamp > nullthrows(operation.endTime).valueOf()
             ) {
               getTracker()?.track('OptimisticFilesStateForceResolved', {extras: {}});
               files = true;
@@ -422,7 +422,7 @@ export function useMarkOperationsCompleted(): void {
               conflicts = true;
             } else if (
               (mergeConflictsContext.conflicts?.fetchStartTimestamp ?? 0) >
-              unwrap(operation.endTime).valueOf()
+              nullthrows(operation.endTime).valueOf()
             ) {
               getTracker()?.track('OptimisticConflictsStateForceResolved', {
                 extras: {operation: getOpName(operation.operation)},
diff --git a/addons/isl/src/stackEdit/__tests__/commitStackState.test.ts b/addons/isl/src/stackEdit/__tests__/commitStackState.test.ts
index 82a8680e8ec9e..57a8c7b153ba5 100644
--- a/addons/isl/src/stackEdit/__tests__/commitStackState.test.ts
+++ b/addons/isl/src/stackEdit/__tests__/commitStackState.test.ts
@@ -11,7 +11,7 @@ import type {ExportCommit, ExportStack} from 'shared/types/stack';
 import {ABSENT_FILE, CommitIdx, CommitStackState, CommitState} from '../commitStackState';
 import {FileStackState} from '../fileStackState';
 import {List, Set as ImSet, Map as ImMap} from 'immutable';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 const exportCommitDefault: ExportCommit = {
   requested: true,
@@ -882,7 +882,7 @@ describe('CommitStackState', () => {
     const emptyStack = subStack.set('stack', List());
 
     const getChangedFiles = (state: CommitStackState, rev: Rev): Array<string> => {
-      return [...unwrap(state.stack.get(rev)).files.keys()].sort();
+      return [...nullthrows(state.stack.get(rev)).files.keys()].sort();
     };
 
     it('optimizes file changes by removing unmodified changes', () => {
@@ -900,7 +900,7 @@ describe('CommitStackState', () => {
       // Change the 2nd commit in subStack to empty.
       const newSubStack = subStack.set(
         'stack',
-        subStack.stack.setIn([1, 'files'], unwrap(subStack.stack.get(0)).files),
+        subStack.stack.setIn([1, 'files'], nullthrows(subStack.stack.get(0)).files),
       );
       // `applySubStack` should drop the 2nd commit in `newSubStack`.
       const newStack = stack.applySubStack(2, 4, newSubStack);
@@ -947,7 +947,7 @@ describe('CommitStackState', () => {
     });
 
     it('update keys to avoid conflict', () => {
-      const oldKey = unwrap(stack.stack.get(1)).key;
+      const oldKey = nullthrows(stack.stack.get(1)).key;
       const newSubStack = subStack.set('stack', subStack.stack.setIn([0, 'key'], oldKey));
       const newStack = stack.applySubStack(2, 3, newSubStack);
 
@@ -961,8 +961,10 @@ describe('CommitStackState', () => {
       // x.txt was deleted by subStack rev 0 (B). We are moving it to be deleted by rev 1 (C).
       expect(subStack.getFile(0, 'x.txt').flags).toBe(ABSENT_FILE.flags);
       // To break the deletion into done by 2 commits, we edit the file stack of 'x.txt'.
-      const fileIdx = unwrap(subStack.commitToFile.get(CommitIdx({rev: 0, path: 'x.txt'}))).fileIdx;
-      const fileStack = unwrap(subStack.fileStacks.get(fileIdx));
+      const fileIdx = nullthrows(
+        subStack.commitToFile.get(CommitIdx({rev: 0, path: 'x.txt'})),
+      ).fileIdx;
+      const fileStack = nullthrows(subStack.fileStacks.get(fileIdx));
       // The file stack has 3 revs: (base, before deletion), (deleted at rev 0), (deleted at rev 1).
       expect(fileStack.convertToPlainText().toArray()).toEqual(['33', '', '']);
       const newFileStack = new FileStackState(['33', '3', '']);
@@ -993,8 +995,10 @@ describe('CommitStackState', () => {
     it('does not add ABSENT flag if content becomes empty', () => {
       // This was a herustics when `flags` are not handled properly. Now it is no longer needed.
       // y.txt was added by subStack rev 0 (B). We are moving it to be added by rev 1 (C).
-      const fileIdx = unwrap(subStack.commitToFile.get(CommitIdx({rev: 0, path: 'y.txt'}))).fileIdx;
-      const fileStack = unwrap(subStack.fileStacks.get(fileIdx));
+      const fileIdx = nullthrows(
+        subStack.commitToFile.get(CommitIdx({rev: 0, path: 'y.txt'})),
+      ).fileIdx;
+      const fileStack = nullthrows(subStack.fileStacks.get(fileIdx));
       // The file stack has 3 revs: (base, before add), (add by rev 0), (unchanged by rev 1).
       expect(fileStack.convertToPlainText().toArray()).toEqual(['', '33', '33']);
       const newFileStack = new FileStackState(['', '', '33']);
diff --git a/addons/isl/src/stackEdit/commitStackState.ts b/addons/isl/src/stackEdit/commitStackState.ts
index 90dae1dd06eed..3ca6ef49d0641 100644
--- a/addons/isl/src/stackEdit/commitStackState.ts
+++ b/addons/isl/src/stackEdit/commitStackState.ts
@@ -30,7 +30,7 @@ import deepEqual from 'fast-deep-equal';
 import {Seq, List, Map as ImMap, Set as ImSet, Record, is} from 'immutable';
 import {LRU, cachedMethod} from 'shared/LRU';
 import {SelfUpdate} from 'shared/immutableExt';
-import {firstLine, generatorContains, unwrap, zip} from 'shared/utils';
+import {firstLine, generatorContains, nullthrows, zip} from 'shared/utils';
 
 type CommitStackProps = {
   /**
@@ -407,9 +407,9 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
       if (changedRevs.has(rev)) {
         return revToMark(rev);
       } else {
-        const nodes = unwrap(state.stack.get(rev)).originalNodes;
+        const nodes = nullthrows(state.stack.get(rev)).originalNodes;
         assert(nodes.size === 1, 'unchanged commits should have exactly 1 nodes');
-        return unwrap(nodes.first());
+        return nullthrows(nodes.first());
       }
     };
 
@@ -485,7 +485,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
   parentFile(rev: Rev, path: RepoPath, followRenames = true): [Rev, RepoPath, FileState] {
     let prevRev = -1;
     let prevPath = path;
-    let prevFile = unwrap(this.bottomFiles.get(path));
+    let prevFile = nullthrows(this.bottomFiles.get(path));
     const includeBottom = true;
     const logFile = this.logFile(rev, path, followRenames, includeBottom);
     for (const [logRev, logPath, file] of logFile) {
@@ -716,7 +716,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
                 : ((c: CommitState): [string, boolean] => [
                     c.text.split('\n').at(0) || [...c.originalNodes].at(0) || '?',
                     isAbsent(c.files.get(path)),
-                  ])(unwrap(stack.get(rev)));
+                  ])(nullthrows(stack.get(rev)));
             spans.push(`${commitTitle}/${path}`);
             if (showContent && !absent) {
               spans.push(`(${fileStack.getRev(fileRev)})`);
@@ -730,7 +730,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
 
   /** File name for `fileStacks[index]`. If the file is renamed, return  */
   getFileStackDescription(fileIdx: number): string {
-    const fileStack = unwrap(this.fileStacks.get(fileIdx));
+    const fileStack = nullthrows(this.fileStacks.get(fileIdx));
     const revLength = fileStack.revLength - 1;
     const nameAtFirstRev = this.getFileStackPath(fileIdx, 0);
     const nameAtLastRev = this.getFileStackPath(fileIdx, revLength - 1);
@@ -763,7 +763,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
     if (commitRev == null || commitRev < 0) {
       return undefined;
     }
-    return unwrap(this.stack.get(commitRev));
+    return nullthrows(this.stack.get(commitRev));
   }
 
   /**
@@ -785,7 +785,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
       return file.data;
     }
     if (file.data instanceof FileIdx) {
-      return unwrap(this.fileStacks.get(file.data.fileIdx)).getRev(file.data.fileRev);
+      return nullthrows(this.fileStacks.get(file.data.fileIdx)).getRev(file.data.fileRev);
     } else {
       throw new Error('getUtf8Data called on non-utf8 file.');
     }
@@ -848,7 +848,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
     const depMap = new Map<Rev, Set<Rev>>(state.stack.map(c => [c.rev, new Set()]));
 
     const fileIdxRevToCommitRev = (fileIdx: FileStackIndex, fileRev: Rev): Rev =>
-      unwrap(state.fileToCommit.get(FileIdx({fileIdx, fileRev}))).rev;
+      nullthrows(state.fileToCommit.get(FileIdx({fileIdx, fileRev}))).rev;
 
     // Ask FileStack for dependencies about content edits.
     state.fileStacks.forEach((fileStack, fileIdx) => {
@@ -858,7 +858,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
       fileDepMap.forEach((valueFileRevs, keyFileRev) => {
         const keyCommitRev = toCommitRev(keyFileRev);
         if (keyCommitRev >= 0) {
-          const set = unwrap(depMap.get(keyCommitRev));
+          const set = nullthrows(depMap.get(keyCommitRev));
           valueFileRevs.forEach(fileRev => {
             const rev = toCommitRev(fileRev);
             if (rev >= 0) {
@@ -871,7 +871,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
 
     // Besides, file deletion / addition / renames also introduce dependencies.
     state.stack.forEach(commit => {
-      const set = unwrap(depMap.get(commit.rev));
+      const set = nullthrows(depMap.get(commit.rev));
       commit.files.forEach((file, path) => {
         const [prevRev, prevPath, prevFile] = state.parentFile(commit.rev, path, true);
         if (prevRev >= 0 && (isAbsent(prevFile) !== isAbsent(file) || prevPath !== path)) {
@@ -912,7 +912,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
     if (parentRev == null) {
       return false;
     }
-    const parent = unwrap(this.stack.get(parentRev));
+    const parent = nullthrows(this.stack.get(parentRev));
     if (commit.immutableKind !== 'none' || parent.immutableKind !== 'none') {
       return false;
     }
@@ -942,9 +942,9 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
    * This should only be called when `canFoldDown(rev)` returned `true`.
    */
   foldDown(rev: Rev) {
-    const commit = unwrap(this.stack.get(rev));
-    const parentRev = unwrap(this.singleParentRev(rev));
-    const parent = unwrap(this.stack.get(parentRev));
+    const commit = nullthrows(this.stack.get(rev));
+    const parentRev = nullthrows(this.singleParentRev(rev));
+    const parent = nullthrows(this.stack.get(parentRev));
     let newParentFiles = parent.files;
     const newFiles = commit.files.map((origFile, path) => {
       // Fold copyFrom. `-` means "no change".
@@ -1037,12 +1037,12 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
    */
   drop(rev: Rev): CommitStackState {
     let state = this.useFileStack().inner;
-    const commit = unwrap(state.stack.get(rev));
+    const commit = nullthrows(state.stack.get(rev));
     commit.files.forEach((file, path) => {
       const fileIdxRev: FileIdx | undefined = state.commitToFile.get(CommitIdx({rev, path}));
       if (fileIdxRev != null) {
         const {fileIdx, fileRev} = fileIdxRev;
-        const fileStack = unwrap(state.fileStacks.get(fileIdx));
+        const fileStack = nullthrows(state.fileStacks.get(fileIdx));
         // Drop the rev by remapping it to an unused rev.
         const unusedFileRev = fileStack.source.revLength;
         const newFileStack = fileStack.remapRevs(new Map([[fileRev, unusedFileRev]]));
@@ -1079,7 +1079,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
       );
     } else {
       const revMapFunc = (r: Rev) => (r >= rev ? r + 1 : r);
-      const origParents = unwrap(state.stack.get(rev)).parents;
+      const origParents = nullthrows(state.stack.get(rev)).parents;
       newStack = state.stack
         .map(c => rewriteCommitRevs(c, revMapFunc))
         .flatMap(c => {
@@ -1217,7 +1217,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
       // file revs => commit revs => mapped commit revs => mapped file revs
       const fileRevs = fileStack.revs();
       const commitRevPaths: CommitIdx[] = fileRevs.map(fileRev =>
-        unwrap(state.fileToCommit.get(FileIdx({fileIdx, fileRev}))),
+        nullthrows(state.fileToCommit.get(FileIdx({fileIdx, fileRev}))),
       );
       const commitRevs: Rev[] = commitRevPaths.map(({rev}) => rev);
       const mappedCommitRevs: Rev[] = commitRevs.map(rev => commitRevMap.get(rev) ?? rev);
@@ -1239,7 +1239,7 @@ export class CommitStackState extends SelfUpdate<CommitStackRecord> {
 
     // Update state.stack.
     const newStack = state.stack.map((_commit, rev) => {
-      const commit = unwrap(state.stack.get(order[rev]));
+      const commit = nullthrows(state.stack.get(order[rev]));
       return commit.merge({parents: List(rev > 0 ? [rev - 1] : []), rev});
     });
     state = state.set('stack', newStack);
@@ -1549,7 +1549,7 @@ function convertExportFileToFileState(file: ExportFile | null): FileState {
         ? file.data
         : file.dataBase85
         ? Base85({dataBase85: file.dataBase85})
-        : DataRef(unwrap(file.dataRef)),
+        : DataRef(nullthrows(file.dataRef)),
     copyFrom: file.copyFrom,
     flags: file.flags,
   });
diff --git a/addons/isl/src/stackEdit/ui/FileStackEditPanel.tsx b/addons/isl/src/stackEdit/ui/FileStackEditPanel.tsx
index 07ca232e560e9..eec95a931d01e 100644
--- a/addons/isl/src/stackEdit/ui/FileStackEditPanel.tsx
+++ b/addons/isl/src/stackEdit/ui/FileStackEditPanel.tsx
@@ -23,7 +23,7 @@ import {
 } from '@vscode/webview-ui-toolkit/react';
 import {atom, useAtom} from 'jotai';
 import {useState} from 'react';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 import './VSCodeDropdown.css';
 
@@ -94,7 +94,7 @@ export default function FileStackEditPanel() {
   }
 
   // Properties for file stack editing.
-  const stack = unwrap(commitStack.fileStacks.get(fileIdx));
+  const stack = nullthrows(commitStack.fileStacks.get(fileIdx));
   const getTitle = (rev: Rev) =>
     commitStack.getCommitFromFileStackRev(fileIdx, rev)?.text ??
     t(
diff --git a/addons/isl/src/stackEdit/ui/FileStackEditor.tsx b/addons/isl/src/stackEdit/ui/FileStackEditor.tsx
index 77526a3f343d2..f63531309b0b6 100644
--- a/addons/isl/src/stackEdit/ui/FileStackEditor.tsx
+++ b/addons/isl/src/stackEdit/ui/FileStackEditor.tsx
@@ -20,7 +20,7 @@ import deepEqual from 'fast-deep-equal';
 import {Set as ImSet, Range, List} from 'immutable';
 import React, {useState, useRef, useEffect, useLayoutEffect} from 'react';
 import {mergeBlocks, collapseContextBlocks, diffBlocks, splitLines} from 'shared/diff';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 import './FileStackEditor.css';
 
@@ -89,7 +89,7 @@ export function FileStackEditor(props: EditorProps) {
       for (const div of divs) {
         const child = div.lastChild;
         if (child && selection.containsNode(child, true)) {
-          selIds.push(unwrap(div.dataset.selId));
+          selIds.push(nullthrows(div.dataset.selId));
         }
       }
       setSelectedLineIds(ImSet(selIds));
@@ -372,14 +372,14 @@ function FileStackEditorUnifiedStack(props: EditorRowProps) {
       );
 
       if (textEdit) {
-        const len = Range(b1, b2).reduce((acc, i) => acc + unwrap(lines.get(i)).data.length, 0);
+        const len = Range(b1, b2).reduce((acc, i) => acc + nullthrows(lines.get(i)).data.length, 0);
         nextRangeId(len);
       }
 
       return;
     }
     for (let i = b1; i < b2; ++i) {
-      const line = unwrap(lines.get(i));
+      const line = nullthrows(lines.get(i));
       const checkboxes = revs.map(rev => {
         const checked = line.revs.contains(rev);
         let className = 'checkbox' + (rev > 0 ? ' mutable' : ' immutable');
diff --git a/addons/isl/src/stackEdit/ui/SplitStackEditPanel.tsx b/addons/isl/src/stackEdit/ui/SplitStackEditPanel.tsx
index 0fd7a1786980b..fdce36b2718be 100644
--- a/addons/isl/src/stackEdit/ui/SplitStackEditPanel.tsx
+++ b/addons/isl/src/stackEdit/ui/SplitStackEditPanel.tsx
@@ -39,7 +39,7 @@ import {useContextMenu} from 'shared/ContextMenu';
 import {Icon} from 'shared/Icon';
 import {type LineIdx, splitLines, diffBlocks} from 'shared/diff';
 import {useThrottledEffect} from 'shared/hooks';
-import {firstLine, unwrap} from 'shared/utils';
+import {firstLine, nullthrows} from 'shared/utils';
 
 import './SplitStackEditPanel.css';
 
@@ -580,7 +580,7 @@ function StackRangeSelector() {
   const selectEnd = orderedDrag.end ?? selectStart;
 
   const commits = mutableRevs.map(rev => {
-    const commit = unwrap(commitStack.get(rev));
+    const commit = nullthrows(commitStack.get(rev));
     return (
       <div
         onPointerDown={() => {
@@ -588,7 +588,7 @@ function StackRangeSelector() {
         }}
         onPointerEnter={() => {
           if (dragSelection?.isDragging === true) {
-            setDragSelection(old => ({...unwrap(old), end: rev, endKey: commit.key}));
+            setDragSelection(old => ({...nullthrows(old), end: rev, endKey: commit.key}));
           }
         }}
         key={rev}
@@ -783,7 +783,7 @@ export function SplitFile(props: SplitFileProps) {
       for (const div of divs) {
         const child = div.lastChild;
         if (child && selection.containsNode(child, true)) {
-          selIds.push(unwrap(div.dataset.selId));
+          selIds.push(nullthrows(div.dataset.selId));
         }
       }
 
diff --git a/addons/isl/src/stackEdit/ui/StackEditSubTree.tsx b/addons/isl/src/stackEdit/ui/StackEditSubTree.tsx
index 2637f6b13320b..9b19399f4372a 100644
--- a/addons/isl/src/stackEdit/ui/StackEditSubTree.tsx
+++ b/addons/isl/src/stackEdit/ui/StackEditSubTree.tsx
@@ -24,7 +24,7 @@ import {VSCodeButton} from '@vscode/webview-ui-toolkit/react';
 import {is} from 'immutable';
 import {useRef, useState} from 'react';
 import {Icon} from 'shared/Icon';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 import {getZoomLevel} from 'shared/zoom';
 
 import './StackEditSubTree.css';
@@ -102,7 +102,7 @@ export function StackEditSubTree(props: ActivateSplitProps): React.ReactElement
             name: 'move',
             offset: currentReorderState.offset,
             depCount: currentReorderState.draggingRevs.size - 1,
-            commit: unwrap(commitStack.stack.get(currentReorderState.draggingRev)),
+            commit: nullthrows(commitStack.stack.get(currentReorderState.draggingRev)),
           });
           bumpStackEditMetric('moveDnD');
         }
@@ -168,7 +168,7 @@ export function StackEditCommit({
   const canDrop = state.canDrop(rev);
   const canMoveDown = state.canMoveDown(rev);
   const canMoveUp = state.canMoveUp(rev);
-  const commit = unwrap(state.stack.get(rev));
+  const commit = nullthrows(state.stack.get(rev));
   const titleText = commit.text.split('\n', 1).at(0) ?? '';
 
   const handleMoveUp = () => {
@@ -299,7 +299,7 @@ function calculateReorderOffset(
   invisibleRevCount = 1,
 ): number {
   let belowCount = 0;
-  const parentY: number = unwrap(container).getBoundingClientRect().y;
+  const parentY: number = nullthrows(container).getBoundingClientRect().y;
   container.querySelectorAll('.commit').forEach(element => {
     const commitDiv = element as HTMLDivElement;
     // commitDiv.getBoundingClientRect() will consider the animation transform.
diff --git a/addons/isl/src/stackEdit/ui/stackEditState.ts b/addons/isl/src/stackEdit/ui/stackEditState.ts
index c870ac9c397e3..40e6783ddb28c 100644
--- a/addons/isl/src/stackEdit/ui/stackEditState.ts
+++ b/addons/isl/src/stackEdit/ui/stackEditState.ts
@@ -22,7 +22,7 @@ import {CommitStackState} from '../../stackEdit/commitStackState';
 import {assert, registerDisposable} from '../../utils';
 import {List, Record} from 'immutable';
 import {atom, useAtom} from 'jotai';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 type StackStateWithOperationProps = {
   op: StackEditOpDescription;
@@ -83,7 +83,7 @@ type HistoryRecord = RecordOf<HistoryProps>;
 
 class History extends HistoryRecord {
   get current(): StackStateWithOperation {
-    return unwrap(this.history.get(this.currentIndex));
+    return nullthrows(this.history.get(this.currentIndex));
   }
 
   push(
diff --git a/addons/isl/src/testQueries.ts b/addons/isl/src/testQueries.ts
index 052fd7ce19875..f4ee40b5ecc3c 100644
--- a/addons/isl/src/testQueries.ts
+++ b/addons/isl/src/testQueries.ts
@@ -14,7 +14,7 @@ import {
 import {readAtom} from './jotaiUtils';
 import {screen, within, fireEvent, waitFor} from '@testing-library/react';
 import {act} from 'react-dom/test-utils';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 
 export const CommitTreeListTestUtils = {
   withinCommitTree() {
@@ -49,7 +49,7 @@ export const CommitInfoTestUtils = {
     const commit = within(screen.getByTestId(`commit-${hash}`)).queryByTestId('draggable-commit');
     expect(commit).toBeInTheDocument();
     act(() => {
-      fireEvent.click(unwrap(commit), {metaKey: cmdClick === true});
+      fireEvent.click(nullthrows(commit), {metaKey: cmdClick === true});
     });
   },
 
@@ -77,7 +77,7 @@ export const CommitInfoTestUtils = {
     ).queryByText('Amend');
     expect(amendButton).toBeInTheDocument();
     act(() => {
-      fireEvent.click(unwrap(amendButton));
+      fireEvent.click(nullthrows(amendButton));
     });
   },
 
@@ -87,7 +87,7 @@ export const CommitInfoTestUtils = {
     ).queryByText('Amend Message');
     expect(amendMessageButton).toBeInTheDocument();
     act(() => {
-      fireEvent.click(unwrap(amendMessageButton));
+      fireEvent.click(nullthrows(amendMessageButton));
     });
   },
 
@@ -97,7 +97,7 @@ export const CommitInfoTestUtils = {
     ).queryByText('Commit');
     expect(commitButton).toBeInTheDocument();
     act(() => {
-      fireEvent.click(unwrap(commitButton));
+      fireEvent.click(nullthrows(commitButton));
     });
   },
 
@@ -107,7 +107,7 @@ export const CommitInfoTestUtils = {
     expect(cancelButton).toBeInTheDocument();
 
     act(() => {
-      fireEvent.click(unwrap(cancelButton));
+      fireEvent.click(nullthrows(cancelButton));
     });
   },
 
diff --git a/addons/shared/utils.ts b/addons/shared/utils.ts
index 79b957c2ccacd..219c0986e7733 100644
--- a/addons/shared/utils.ts
+++ b/addons/shared/utils.ts
@@ -14,7 +14,7 @@ export function notEmpty<T>(value: T | null | undefined): value is T {
 /**
  * Throw if value is `null` or `undefined`.
  */
-export function unwrap<T>(value: T | undefined | null): T {
+export function nullthrows<T>(value: T | undefined | null): T {
   if (value == null) {
     throw new Error(`expected value not to be ${value}`);
   }
diff --git a/addons/vscode/extension/__tests__/DiffContentProvider.test.ts b/addons/vscode/extension/__tests__/DiffContentProvider.test.ts
index f25bf7e9a9edc..59e72c961b207 100644
--- a/addons/vscode/extension/__tests__/DiffContentProvider.test.ts
+++ b/addons/vscode/extension/__tests__/DiffContentProvider.test.ts
@@ -18,7 +18,7 @@ import {
 import {makeServerSideTracker} from 'isl-server/src/analytics/serverSideTracker';
 import {ComparisonType} from 'shared/Comparison';
 import {mockLogger} from 'shared/testUtils';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 import * as vscode from 'vscode';
 
 const mockCancelToken = {} as vscode.CancellationToken;
@@ -72,8 +72,8 @@ function mockRepoAdded(): NonNullable<typeof activeRepo> {
       savedOnChangeHeadCommit(commit);
     },
   } as unknown as typeof activeRepo;
-  activeReposCallback?.([unwrap(activeRepo)]);
-  return unwrap(activeRepo);
+  activeReposCallback?.([nullthrows(activeRepo)]);
+  return nullthrows(activeRepo);
 }
 function mockNoActiveRepo() {
   activeRepo = undefined;
diff --git a/addons/vscode/extension/blame/blame.ts b/addons/vscode/extension/blame/blame.ts
index b7856525cd6e7..7e28956d329d4 100644
--- a/addons/vscode/extension/blame/blame.ts
+++ b/addons/vscode/extension/blame/blame.ts
@@ -25,7 +25,7 @@ import {getUsername} from 'isl-server/src/analytics/environment';
 import {relativeDate} from 'isl/src/relativeDate';
 import {LRU} from 'shared/LRU';
 import {debounce} from 'shared/debounce';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 import {DecorationRangeBehavior, MarkdownString, Position, Range, window, workspace} from 'vscode';
 
 function areYouTheAuthor(author: string) {
@@ -278,7 +278,7 @@ export class InlineBlameProvider implements Disposable {
       this.ctx.logger.info(`No blame found for path ${path}`);
     }
 
-    const blameLines = unwrap(blame.value);
+    const blameLines = nullthrows(blame.value);
 
     repoCaches.blameCache.set(fileUri, {
       baseBlameLines: blameLines,
@@ -294,7 +294,7 @@ export class InlineBlameProvider implements Disposable {
     const uri = textEditor.document.uri.fsPath;
     const repo = this.reposList.repoForPath(uri)?.repo;
     try {
-      return {value: await unwrap(repo).blame(this.ctx, uri, baseHash)};
+      return {value: await nullthrows(repo).blame(this.ctx, uri, baseHash)};
     } catch (err: unknown) {
       return {error: err as Error};
     }
@@ -363,7 +363,7 @@ export class InlineBlameProvider implements Disposable {
       this.updateBlame(this.currentEditor.document);
     }
 
-    const blameLines = unwrap(revisionSet.currentBlameLines);
+    const blameLines = nullthrows(revisionSet.currentBlameLines);
     if (line >= blameLines.length) {
       return undefined;
     }
diff --git a/addons/vscode/extension/islWebviewPanel.ts b/addons/vscode/extension/islWebviewPanel.ts
index 5c7de7ebbbab2..93646191d1141 100644
--- a/addons/vscode/extension/islWebviewPanel.ts
+++ b/addons/vscode/extension/islWebviewPanel.ts
@@ -17,7 +17,7 @@ import {locale, t} from './i18n';
 import crypto from 'crypto';
 import {onClientConnection} from 'isl-server/src';
 import {deserializeFromString, serializeToString} from 'isl/src/serialize';
-import {unwrap} from 'shared/utils';
+import {nullthrows} from 'shared/utils';
 import * as vscode from 'vscode';
 
 let islPanelOrView: vscode.WebviewPanel | vscode.WebviewView | undefined = undefined;
@@ -48,7 +48,7 @@ function createOrFocusISLWebview(
     platform,
     logger,
   );
-  return unwrap(islPanelOrView);
+  return nullthrows(islPanelOrView);
 }
 
 function getWebviewOptions(