Support TypeScript 7.1 API

.claude/settings.json

@@ -0,0 +1,38 @@
+{
+  "permissions": {
+    "defaultMode": "dontAsk",
+    "allow": [
+      "Edit",
+      "Write",
+      "Bash(rm -rf .spike-tmp*)",
+      "Bash(yarn build *)",
+      "Bash(yarn lint *)",
+      "Bash(yarn format *)",
+      "Bash(yarn test *)",
+      "Bash(yarn comparison-tests *)",
+      "Bash(yarn execution-tests *)",
+      "Bash(yarn clean *)",
+      "Bash(yarn install *)",
+      "Bash(git status *)",
+      "Bash(git diff *)",
+      "Bash(git log *)",
+      "Bash(git stash *)",
+      "Bash(git checkout *)",
+      "Bash(git clean *)",
+      "Bash(npm ls *)",
+      "Bash(npm view *)",
+      "Bash(npm root *)",
+      "Bash(npm config *)",
+      "Bash(node *)",
+      "Bash(node_modules/.bin/tsc *)",
+      "Bash(npx tsc *)",
+      "Bash(npx mocha *)",
+      "Bash(grep *)",
+      "Read(//usr/local/lib/node_modules/**)",
+      "Bash(rm -rf .test)",
+      "Bash(FORCE_COLOR=1 node node_modules/mocha/bin/_mocha test/comparison-tests/create-and-execute-test.js --reporter spec --test-to-run * --timeout 25000)",
+      "Bash(node node_modules/mocha/bin/_mocha test/comparison-tests/create-and-execute-test.js --reporter spec --test-to-run * --timeout 25000)",
+      "Bash(echo \"PID $!\")"
+    ]
+  }
+}

.devcontainer/devcontainer.json

@@ -17,7 +17,7 @@
 
 	// Add the IDs of extensions you want installed when the container is created.
 	"extensions": [
-		"dbaeumer.vscode-eslint",
+		"oxc.oxc-vscode",
 		"esbenp.prettier-vscode"
 	],
 

.github/workflows/push.yml

@@ -53,7 +53,7 @@ jobs:
     strategy:
       matrix:
         node: [26, 24, 22]
-        ts: [5.6.2, 5.7.2, 5.8.2, 5.9.2, 6.0.2] # next excluded for now
+        ts: [7.1.0-dev.20260829.1, next]
         webpack: [4, 5]
     runs-on: ubuntu-latest
     steps:
@@ -85,7 +85,7 @@ jobs:
     strategy:
       matrix:
         node: [26, 24, 22]
-        ts: [5.6.2, 5.7.2, 5.8.2, 5.9.2, 6.0.2] # next excluded for now
+        ts: [7.1.0-dev.20260829.1, next]
         webpack: [4, 5]
     runs-on: windows-latest
     steps:
@@ -134,3 +134,27 @@ jobs:
 
       - name: lint
         run: yarn lint
+
+  format:
+    name: Format
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: install
+        run: yarn install
+
+      - name: format:check
+        run: yarn format:check
+
+  knip:
+    name: Knip
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v7
+
+      - name: install
+        run: yarn install
+
+      - name: knip
+        run: yarn knip

.gitignore

@@ -14,13 +14,13 @@ npm-debug.log
 !/test/**/expectedOutput-transpile/**
 /**/node_modules
 /dist
+/dist-2018
 /test/execution-tests/**/dist
-/**/.happypack
 /**/.cache-loader
 !build.js
 /**/debug.log
 .pnp
 .pnp.js
-!.eslintrc.js
 .vs/**
-.pnpm-store
+.pnpm-store
+.spike-tmp

.oxlintrc.json

@@ -0,0 +1,30 @@
+{
+  "$schema": "./node_modules/oxlint/configuration_schema.json",
+  "plugins": ["typescript", "unicorn", "oxc"],
+  "categories": {
+    "correctness": "error"
+  },
+  "options": {
+    "typeAware": true,
+    "typeCheck": true
+  },
+  "rules": {
+    "typescript/unbound-method": "off",
+    "typescript/consistent-type-imports": "error",
+    "no-unused-vars": [
+      "error",
+      {
+        "args": "all",
+        "argsIgnorePattern": "^_",
+        "caughtErrors": "all",
+        "caughtErrorsIgnorePattern": "^_",
+        "destructuredArrayIgnorePattern": "^_",
+        "varsIgnorePattern": "^_",
+        "ignoreRestSiblings": true
+      }
+    ]
+  },
+  "env": {
+    "builtin": true
+  }
+}

.vscode/extensions.json

@@ -1,6 +1,6 @@
 {
   "recommendations": [
-    "dbaeumer.vscode-eslint",
+    "oxc.oxc-vscode",
     "esbenp.prettier-vscode"
   ]
 }

.vscode/settings.json

@@ -8,5 +8,6 @@
     "sed": true,
     "yarn": true,
     "git check-ignore": true
-  }
+  },
+  "editor.formatOnSave": true
 }

AGENTS.md

@@ -6,20 +6,31 @@ ts-loader is a TypeScript loader for webpack, enabling webpack to compile `.ts`
 
 Use `yarn` (not npm).
 
+## Style
+
+Prefer function declarations for named functions, especially reusable helpers. Use `function name(...) {}` instead of `const name = (...) => {}` when the function needs a name, as this is generally preferred for readability and consistency.
+
+Prefer `interface` over `type` for object shapes when possible, as interfaces have better performance and tooling support in TypeScript.
+
+## Comments
+
+Keep comments in `src/` sparse: only the non-obvious _why_ (a Windows-only path quirk, an undocumented API behavior, a deliberate divergence from classic ts-loader's output) earns one, and it should be as short as it can be while still saying that. Don't add a comment that restates what a well-named identifier or the code's own shape already makes clear. Before trimming or removing an existing comment, weigh what it would cost to rediscover - some encode a hard-won finding (a repro script, a real Windows CI failure) that isn't obvious from the code alone; when in doubt, shorten rather than delete. `src/typeScriptApi.ts` is the densest file by necessity (most of ts-loader's TypeScript-API-specific behavior lives there); see "Testing on Windows CI" below for its most common recurring gotcha.
+
 ## Key commands
 
 Note: test scripts clean test directories first using `git clean -xfd`.
 
 ```bash
 yarn build              # compile src/ → dist/ (tsc --project "./src")
-yarn lint               # type-check + ESLint (no separate typecheck script)
+yarn lint               # type-check + oxlint (no separate typecheck script)
 yarn test               # full test suite (comparison + execution tests)
 yarn comparison-tests   # fast subset: compare webpack output against snapshots
 yarn execution-tests    # run compiled code via Karma/Jasmine
 yarn benchmark          # compare this build's compile speed against another ts-loader checkout
 ```
 
 To run a single test:
+
 ```bash
 yarn comparison-tests -- --single-test <testName>
 yarn execution-tests  -- --single-test <testName> --watch
@@ -36,7 +47,7 @@ Full docs: [`test/comparison-tests/README.md`](test/comparison-tests/README.md)
 **Flaky tests**: place an empty `_FLAKY_` file in the test directory to allow occasional failures without blocking the build.
 
 ```bash
-yarn comparison-tests                                              # all tests
+yarn comparison-tests                                             # all tests
 yarn comparison-tests -- --single-test <name>                     # one test
 yarn comparison-tests -- --save-output                            # regenerate all snapshots
 yarn comparison-tests -- --save-output --single-test <name>       # regenerate one snapshot
@@ -53,9 +64,12 @@ Full docs: [`test/execution-tests/README.md`](test/execution-tests/README.md)
 Tests prefixed with a TypeScript version (e.g. `2.0.3_es2016`) are skipped when the installed TypeScript is older than that prefix.
 
 Every `webpack.config.js` in this pack must include this alias so the local ts-loader is resolved:
+
 ```js
 // for test harness purposes only
-module.exports.resolveLoader = { alias: { 'ts-loader': path.join(__dirname, "../../../index.js") } }
+module.exports.resolveLoader = {
+  alias: { 'ts-loader': path.join(__dirname, '../../../index.js') },
+};
 ```
 
 ```bash
@@ -64,6 +78,31 @@ yarn execution-tests -- --single-test <name>            # one test
 yarn execution-tests -- --single-test <name> --watch    # watch mode (open http://localhost:9876/)
 ```
 
+## Testing on Windows CI
+
+macOS/Linux passing locally does **not** mean Windows passes — this codebase has repeatedly had Windows-only comparison-test failures with no macOS/Linux equivalent. The recurring root cause: `src/typeScriptApi.ts` calls into the TypeScript API (`typescript/unstable/sync`), whose `program.getSourceFileNames()`/`getConfigFileNames()`/internal lookups return forward-slash-normalized paths on every OS (the long-standing TS compiler convention), while Node's own `path.resolve`/`path.join`/`path.normalize` return OS-native (backslash on Windows) paths. Any place that builds a path with Node's `path` module and then compares it against, or hands it to, something expecting the API's own spelling — a `Set`/`Map` keyed by API-returned names, or webpack's `addDependency`/`addBuildDependency` (which rejects non-native absolute paths) — silently breaks on Windows only. When investigating a new Windows-only failure, check for this pattern first (search for `path.resolve`/`path.join`/`path.normalize` near any `program.get*`/`toComparablePath` usage in `src/typeScriptApi.ts`).
+
+### Windows test probe workflow
+
+`.github/workflows/windows-test-probe.yml` (registered on `main`, so dispatchable against any branch/ref) runs just the Windows comparison tests via `workflow_dispatch` — much faster than the full `push.yml` matrix (which also runs the Ubuntu suite and the full Node/TS/webpack execution-test matrix). Use it to iterate on Windows-only failures without asking a human to relay CI output.
+
+Requires `gh` CLI authenticated with the `workflow` scope (`gh auth login`, then `gh auth refresh -s workflow` if `gh auth status` doesn't already list `workflow` — both scopes need a human to complete the browser device-flow prompt, they can't be scripted).
+
+````bash
+# trigger — omit both inputs to run the full comparison-test suite
+gh workflow run windows-test-probe.yml --repo TypeStrong/ts-loader \
+  --ref <branch> -f single_test=<name>            # one test
+gh workflow run windows-test-probe.yml --repo TypeStrong/ts-loader \
+  --ref <branch> -f match_test='^(testA|testB)$'  # several, by regex
+
+# the trigger command prints the run URL directly - grab the numeric id from it, then:
+gh run watch <run-id> --repo TypeStrong/ts-loader --exit-status   # blocks until done
+
+# `gh run watch` can itself fail on a transient network blip even when the run
+# succeeded - always verify conclusion this way rather than trusting its exit code
+gh run view <run-id> --repo TypeStrong/ts-loader --json status,conclusion
+
+gh run view <run-id> --repo TypeStrong/ts-loader --log-failed    # full failure log text
 ## Benchmark tests (`test/benchmark-tests/`)
 
 Answers "did this get faster or slower?", not "is the output correct?" - the comparison/execution packs never record timing, so this is a separate harness. It generates a synthetic project on the fly and times ts-loader compiling it (cold build, and incremental rebuild after touching a low-fan-out vs. high-fan-out file, under both `transpileOnly: true`/`false`), comparing two ts-loader checkouts (this build vs. another, e.g. `main`) back-to-back in one process so the relative numbers are meaningful despite noisy CI hosts.
@@ -75,6 +114,6 @@ Full docs: [`test/benchmark-tests/README.md`](test/benchmark-tests/README.md)
 ```bash
 yarn benchmark -- --root-a . --root-b .                # sanity check against itself, expect ~0% deltas
 yarn benchmark -- --root-a . --root-b ../ts-loader-main # compare against another built checkout
-```
+````
 
 Always add or update tests when fixing bugs or adding features — see [CONTRIBUTING.md](CONTRIBUTING.md).