Add support for incremental builds

Re: #26

README.md

@@ -650,6 +650,10 @@ you may have packages that depend on one another and are all
 being built in parallel (as long as they've been built one time,
 of course).
 
+If you use `"incremental": true` in your tsconfig, then this
+folder will persist, so that TSC can benefit from the
+`.tsbuildinfo` files it creates in there.
+
 ## Exports Management
 
 The `exports` field in your package.json file will be updated

src/build.ts

@@ -18,9 +18,10 @@ import {
 } from './self-dep.js'
 import './tsconfig.js'
 import writePackage from './write-package.js'
+import cleanBuildTmp from './clean-build-tmp.js'
 
 export default async () => {
-  rimrafSync('.tshy-build-tmp')
+  cleanBuildTmp()
 
   linkSelfDep(pkg, 'src')
   await linkImports(pkg, 'src')
@@ -31,8 +32,9 @@ export default async () => {
 
   console.debug(chalk.cyan.dim('moving to ./dist'))
   syncContentSync('.tshy-build-tmp', 'dist')
-  console.debug(chalk.cyan.dim('removing build temp dir'))
-  rimrafSync('.tshy-build-tmp')
+  console.debug(chalk.cyan.dim('cleaning build temp dir'))
+
+  cleanBuildTmp()
 
   linkSelfDep(pkg, 'dist')
 

src/clean-build-tmp.ts

@@ -0,0 +1,86 @@
+// Remove the .tshy-build-tmp folder, but ONLY if
+// the "incremental" config value is not set, or if
+// it does not contain any tsbuildinfo files.
+// If we are in incremental mode, and have tsbuildinfo files,
+// then find and remove any files here that do not have a matching
+// source file in ./src
+
+import { readdirSync } from 'fs'
+import { parse } from 'path'
+import { rimrafSync } from 'rimraf'
+import * as console from './console.js'
+import readTypescriptConfig from './read-typescript-config.js'
+
+const cleanRemovedOutputs = (path: string, root: string) => {
+  const entries = readdirSync(`${root}/${path}`, {
+    withFileTypes: true,
+  })
+  let sources: Set<string> | undefined = undefined
+  try {
+    sources = new Set(readdirSync(`src/${path}`))
+  } catch {}
+  // directory was removed
+  if (!sources) {
+    return rimrafSync(`${root}/${path}`)
+  }
+  for (const e of entries) {
+    const outputFile = `${path}/${e.name}`
+    if (e.isDirectory()) {
+      cleanRemovedOutputs(outputFile, root)
+      continue
+    }
+    let { ext, name } = parse(outputFile)
+    if (ext === '.map') {
+      continue
+    }
+    if (name.endsWith('.d') && ext.endsWith('ts')) {
+      ext = '.d' + ext
+      name = name.substring(0, name.length - '.d'.length)
+    }
+
+    const inputSearch =
+      ext === '.js' || ext === '.d.ts'
+        ? ['.tsx', '.ts']
+        : ext === '.mjs' || ext === '.d.mts'
+        ? ['.mts']
+        : ext === '.cjs' || ext === '.d.cts'
+        ? ['.cts']
+        : []
+    inputSearch.push(ext)
+    let del = true
+    for (const ext of inputSearch) {
+      if (sources.has(`${name}${ext}`)) {
+        del = false
+        break
+      }
+    }
+    if (del) {
+      console.debug('removing output file', outputFile)
+      rimrafSync([
+        `${root}/${outputFile}`,
+        `${root}/${outputFile}.map`,
+      ])
+    }
+  }
+}
+
+export default () => {
+  const config = readTypescriptConfig()
+  if (config.options.incremental !== true) {
+    return rimrafSync('.tshy-build-tmp')
+  }
+
+  let buildInfos: string[] | undefined = undefined
+  try {
+    buildInfos = readdirSync('.tshy-build-tmp/.tshy')
+  } catch {}
+  if (!buildInfos?.length) {
+    return rimrafSync('.tshy-build-tmp')
+  }
+
+  // delete anything that has been removed from src.
+  for (const dialect of readdirSync('.tshy-build-tmp')) {
+    if (dialect === '.tshy') continue
+    cleanRemovedOutputs('.', `.tshy-build-tmp/${dialect}`)
+  }
+}

src/prevent-verbatim-module-syntax.ts

@@ -3,20 +3,12 @@
 // be made to work in a hybrid context.
 // Note: cannot just use JSON.parse, because ts config files
 // are jsonc.
-import { resolve } from 'path'
-import ts from 'typescript'
 import * as console from './console.js'
 import fail from './fail.js'
-const { readFile } = ts.sys
+import readTypescriptConfig from './read-typescript-config.js'
 
 export default () => {
-  const configPath = resolve('tsconfig.json')
-  const readResult = ts.readConfigFile(configPath, readFile)
-  const config = ts.parseJsonConfigFileContent(
-    readResult.config,
-    ts.sys,
-    process.cwd()
-  )
+  const config = readTypescriptConfig()
   if (config.options.verbatimModuleSyntax) {
     fail('verbatimModuleSyntax detected')
     console.error(

src/read-typescript-config.ts

@@ -0,0 +1,18 @@
+// read the actual configuration that tsc is using
+// Note: cannot just use JSON.parse, because ts config files
+// are jsonc.
+import { resolve } from 'path'
+import ts from 'typescript'
+const { readFile } = ts.sys
+
+let parsedTsConfig: ts.ParsedCommandLine | undefined = undefined
+export default () => {
+  if (parsedTsConfig) return parsedTsConfig
+  const configPath = resolve('tsconfig.json')
+  const readResult = ts.readConfigFile(configPath, readFile)
+  return (parsedTsConfig = ts.parseJsonConfigFileContent(
+    readResult.config,
+    ts.sys,
+    process.cwd()
+  ))
+}

tap-snapshots/test/prevent-verbatim-module-syntax.ts.test.cjs

@@ -5,7 +5,7 @@
  * Make sure to inspect the output below.  Do not ignore changes!
  */
 'use strict'
-exports[`test/prevent-verbatim-module-syntax.ts > TAP > not set, no worries > must match snapshot 1`] = `
+exports[`test/prevent-verbatim-module-syntax.ts > TAP > is set, many worries > must match snapshot 1`] = `
 verbatimModuleSyntax detected
 verbatimModuleSyntax is incompatible with multi-dialect builds. Either remove
 this field from tsconfig.json, or set a single dialect in the "dialects"

test/clean-build-tmp.ts

@@ -0,0 +1,79 @@
+import { statSync } from 'fs'
+import t from 'tap'
+import cleanBuildTmp from '../src/clean-build-tmp.js'
+import readTypescriptConfig from '../src/read-typescript-config.js'
+const cwd = process.cwd()
+t.afterEach(() => process.chdir(cwd))
+
+t.test('no incremental build, just delete it', t => {
+  readTypescriptConfig().options.incremental = false
+  process.chdir(
+    t.testdir({
+      '.tshy-build-tmp': {},
+    })
+  )
+  cleanBuildTmp()
+  t.throws(() => statSync('.tshy-build-tmp'))
+  t.end()
+})
+
+t.test('no tsbuildinfo, just delete it', t => {
+  readTypescriptConfig().options.incremental = true
+  process.chdir(
+    t.testdir({
+      '.tshy-build-tmp': {},
+    })
+  )
+  cleanBuildTmp()
+  t.throws(() => statSync('.tshy-build-tmp'))
+  t.end()
+})
+
+t.test('remove files not found in src', t => {
+  readTypescriptConfig().options.incremental = true
+  process.chdir(
+    t.testdir({
+      '.tshy-build-tmp': {
+        '.tshy': { 'esm.tsbuildinfo': '{}' },
+        esm: {
+          'a.d.ts': '',
+          'a.js': '',
+          'a.js.map': '',
+          'a.d.ts.map': '',
+          'a.jsx': '',
+          'a.jsx.map': '',
+          dir: {
+            'b.d.ts': '',
+            'b.js': '',
+            'b.js.map': '',
+            'b.d.ts.map': '',
+          },
+          'x.d.ts': '',
+          'x.js': '',
+          'x.js.map': '',
+          'x.d.ts.map': '',
+          'm.mjs': '',
+          'm.d.mts': '',
+          'c.cjs': '',
+          'c.d.cts': '',
+          xdir: {
+            'x.d.ts': '',
+            'x.js': '',
+            'x.js.map': '',
+            'x.d.ts.map': '',
+          },
+        },
+      },
+      src: {
+        'a.tsx': '',
+        dir: {
+          'b.ts': '',
+        },
+      },
+    })
+  )
+  cleanBuildTmp()
+  t.throws(() => statSync('.tshy-build-tmp/dist/esm/x.js.map'))
+  t.throws(() => statSync('.tshy-build-tmp/dist/esm/x.d.ts'))
+  t.end()
+})

test/prevent-verbatim-module-syntax.ts

@@ -1,5 +1,6 @@
 import chalk from 'chalk'
 import t from 'tap'
+import readTypescriptConfig from '../src/read-typescript-config.js'
 import preventVerbatimModuleSyntax from '../src/prevent-verbatim-module-syntax.js'
 
 chalk.level = 3
@@ -16,17 +17,8 @@ t.test('not set, no worries', t => {
   t.end()
 })
 
-t.test('not set, no worries', t => {
-  const cwd = process.cwd()
-  process.chdir(
-    t.testdir({
-      'tsconfig.json': JSON.stringify({
-        compilerOptions: {
-          verbatimModuleSyntax: true,
-        },
-      }),
-    })
-  )
+t.test('is set, many worries', t => {
+  readTypescriptConfig().options.verbatimModuleSyntax = true
   preventVerbatimModuleSyntax()
   t.strictSame(exits(), [[1]])
   t.matchSnapshot(
@@ -35,6 +27,5 @@ t.test('not set, no worries', t => {
       .join('\n')
   )
   t.strictSame(logs(), [])
-  process.chdir(cwd)
   t.end()
 })

test/read-typescript-config.ts

@@ -0,0 +1,5 @@
+import t from 'tap'
+import readTypescriptConfig from '../src/read-typescript-config.js'
+
+const config = readTypescriptConfig()
+t.equal(config, readTypescriptConfig(), 'cached')

tsconfig.json

@@ -12,6 +12,8 @@
     "sourceMap": true,
     "strict": true,
     "target": "es2022",
-    "module": "nodenext"
+    "module": "nodenext",
+    "composite": true,
+    "incremental": true
   }
 }