Expose helper WKT methods (#263)

Exposes the WKT helper method previously known as `matchWkt`. This
method helps to transform a general `DescMessage` into a more concrete
`DescWkt` type, which allows for easier access to the WKT's fields.
Useful during code generation functionality.

packages/protobuf/src/codegen-info.ts

@@ -15,6 +15,7 @@
 import { localName } from "./private/names.js";
 import { getUnwrappedFieldType } from "./private/field-wrapper.js";
 import { scalarDefaultValue } from "./private/scalars.js";
+import { reifyWkt } from "./private/reify-wkt.js";
 
 interface CodegenInfo {
   readonly packageName: string;
@@ -23,6 +24,7 @@ interface CodegenInfo {
   readonly getUnwrappedFieldType: typeof getUnwrappedFieldType;
   readonly wktSourceFiles: readonly string[];
   readonly scalarDefaultValue: typeof scalarDefaultValue;
+  readonly reifyWkt: typeof reifyWkt;
 }
 
 type RuntimeSymbolName =
@@ -55,6 +57,7 @@ const packageName = "@bufbuild/protobuf";
 export const codegenInfo: CodegenInfo = {
   packageName,
   localName,
+  reifyWkt,
   getUnwrappedFieldType,
   scalarDefaultValue,
   // prettier-ignore

packages/protoc-gen-es/src/match-wkt.ts → packages/protobuf/src/private/reify-wkt.ts

@@ -12,12 +12,8 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {
-  DescField,
-  DescMessage,
-  DescOneof,
-  ScalarType,
-} from "@bufbuild/protobuf";
+import type { DescField, DescMessage, DescOneof } from "../descriptor-set.js";
+import { ScalarType } from "../field.js";
 
 type DescWkt =
   | {
@@ -94,7 +90,18 @@ type DescWkt =
       value: DescField & { fieldKind: "scalar" };
     };
 
-export function matchWkt(message: DescMessage): DescWkt | undefined {
+/**
+ * Reifies a given DescMessage into a more concrete object representing its
+ * respective well-known type.  The returned object will contain properties
+ * representing the WKT's defined fields.
+ *
+ * Useful during code generation when immediate access to a particular field
+ * is needed without having to search the object's typename and DescField list.
+ *
+ * Returns undefined if the WKT cannot be completely constructed via the
+ * DescMessage.
+ */
+export function reifyWkt(message: DescMessage): DescWkt | undefined {
   switch (message.typeName) {
     case "google.protobuf.Any": {
       const typeUrl = message.fields.find(

packages/protoc-gen-es/src/declaration.ts

@@ -28,8 +28,8 @@ import {
   literalString,
   localName,
   makeJsDoc,
+  reifyWkt,
 } from "@bufbuild/protoplugin/ecmascript";
-import { matchWkt } from "./match-wkt.js";
 
 export function generateDts(schema: Schema) {
   for (const file of schema.files) {
@@ -145,7 +145,7 @@ function generateField(schema: Schema, f: GeneratedFile, field: DescField) {
 
 // prettier-ignore
 function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }
@@ -190,7 +190,7 @@ function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessa
 
 // prettier-ignore
 function generateWktStaticMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }

packages/protoc-gen-es/src/javascript.ts

@@ -24,8 +24,8 @@ import {
   literalString,
   localName,
   makeJsDoc,
+  reifyWkt,
 } from "@bufbuild/protoplugin/ecmascript";
-import { matchWkt } from "./match-wkt.js";
 
 export function generateJs(schema: Schema) {
   for (const file of schema.files) {
@@ -157,7 +157,7 @@ export function generateFieldInfo(schema: Schema, f: GeneratedFile, field: DescF
 
 // prettier-ignore
 function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }
@@ -516,7 +516,7 @@ function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessa
 
 // prettier-ignore
 function generateWktStaticMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }

packages/protoc-gen-es/src/typescript.ts

@@ -29,8 +29,8 @@ import {
   getFieldIntrinsicDefaultValue,
   getFieldTyping,
   makeJsDoc,
+  reifyWkt,
 } from "@bufbuild/protoplugin/ecmascript";
-import { matchWkt } from "./match-wkt.js";
 import { generateFieldInfo } from "./javascript.js";
 import { literalString } from "@bufbuild/protoplugin/ecmascript";
 
@@ -175,7 +175,7 @@ function generateField(schema: Schema, f: GeneratedFile, field: DescField) {
 
 // prettier-ignore
 function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }
@@ -540,7 +540,7 @@ function generateWktMethods(schema: Schema, f: GeneratedFile, message: DescMessa
 
 // prettier-ignore
 function generateWktStaticMethods(schema: Schema, f: GeneratedFile, message: DescMessage) {
-  const ref = matchWkt(message);
+  const ref = reifyWkt(message);
   if (ref === undefined) {
     return;
   }

packages/protoplugin/src/ecmascript/index.ts

@@ -20,7 +20,7 @@ export { RuntimeImports } from "./runtime-imports.js";
 export { GeneratedFile, FileInfo, Printable } from "./generated-file.js";
 export { ImportSymbol } from "./import-symbol.js";
 
-export const { localName } = codegenInfo;
+export const { localName, reifyWkt } = codegenInfo;
 
 export {
   createJsDocBlock,