Dependency audit (#10239)

Had copilot do an audit of all our dependencies to see which ones were
not used, which ones should use a more modern or built in alternative.


### Removed unused dependencies
| Dependency | Packages affected | Reason |
|---|---|---|
| `json5` | `internal-build-utils` | Unused |
| `grammarkdown` | `compiler` | Unused |
| `date-fns` | `website` | Unused |


### Replaced with built in 
| Dependency | Packages affected | Reason |
|---|---|---|
| `c8` | ~25 packages | Unused; coverage handled by
`@vitest/coverage-v8` |
| `deep-equal` / `@types/deep-equal` | `spec-api`, `spector`,
`http-specs` | Replaced with Node.js built-in `isDeepStrictEqual` from
`node:util` |
| `body-parser` / `@types/body-parser` | `spector` | Replaced with
Express 5 built-ins (`express.json()`, `express.urlencoded()`, etc.) |
| `fs-extra` | `http-server-csharp`, `http-server-js`, `http-client-js`
| Replaced with `fs/promises` (`access`, `copyFile`, `mkdir`, etc.) |

### Modernized dependencies

| Old | New | Packages affected | Notes |
|---|---|---|---|
| `onigasm` | `vscode-oniguruma` | `tmlanguage-generator` | Updated WASM
loading and regex validation logic |
| `inquirer` | `@inquirer/prompts` | `http-server-csharp`,
`http-server-js`, `http-client-js` | Switched to modern modular
`select()` API |
| `rimraf` | `fs.rm()` | `typespec-vscode` | Uses `rm(dir, { recursive:
true, force: true })` |

### Code changes

- Emit scenario scripts in `http-server-csharp`, `http-server-js`, and
`http-client-js` updated to use native `fs/promises` and
`@inquirer/prompts`
- A local `pathExists()` helper added to replace the `fs-extra` version
- `tmlanguage-generator` migrated from `onigasm` to `vscode-oniguruma`,
including updated WASM loading and regex validation logic (also removed
a workaround for an `onigasm` bug)
- `@typespec/spector` mock API server replaced `bodyParser.*` calls with
`express.*` equivalents
- `@typespec/spec-api` and `@typespec/spector` replaced all
`deepEqual(a, b, { strict: true })` calls with `isDeepStrictEqual(a, b)`
- pnpm catalog and lockfile cleaned up, removing many transitive
dependencies

Author: timotheeguerin

.chronus/changes/dependency-audit-2026-3-1-19-4-24.md

@@ -0,0 +1,35 @@
+---
+# Change versionKind to one of: internal, fix, dependencies, feature, deprecation, breaking
+changeKind: internal
+packages:
+  - "@typespec/asset-emitter"
+  - "@typespec/bundler"
+  - "@typespec/compiler"
+  - "@typespec/eslint-plugin"
+  - "@typespec/events"
+  - "@typespec/html-program-viewer"
+  - "@typespec/http-client-js"
+  - "@typespec/http-server-csharp"
+  - "@typespec/http-server-js"
+  - "@typespec/http-specs"
+  - "@typespec/http"
+  - "@typespec/internal-build-utils"
+  - "@typespec/json-schema"
+  - "@typespec/library-linter"
+  - "@typespec/openapi"
+  - "@typespec/openapi3"
+  - "@typespec/playground"
+  - "@typespec/protobuf"
+  - "@typespec/rest"
+  - "@typespec/spec-api"
+  - "@typespec/spector"
+  - "@typespec/sse"
+  - "@typespec/streams"
+  - tmlanguage-generator
+  - "@typespec/tspd"
+  - typespec-vscode
+  - "@typespec/versioning"
+  - "@typespec/xml"
+---
+
+Dependency audit

packages/asset-emitter/package.json

@@ -49,7 +49,6 @@
     "@typespec/compiler": "workspace:^",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vitest": "catalog:"

packages/best-practices/package.json

@@ -48,7 +48,6 @@
     "@typespec/compiler": "workspace:^",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vitest": "catalog:"

packages/bundle-uploader/package.json

@@ -42,7 +42,6 @@
     "@pnpm/workspace.find-packages": "catalog:",
     "@typespec/bundler": "workspace:^",
     "globby": "catalog:",
-    "json5": "catalog:",
     "picocolors": "catalog:",
     "semver": "catalog:"
   },
@@ -51,7 +50,6 @@
     "@types/semver": "catalog:",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vitest": "catalog:"

packages/bundler/package.json

@@ -53,7 +53,6 @@
     "@types/yargs": "catalog:",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vite": "catalog:",

packages/compiler/package.json

@@ -132,8 +132,6 @@
     "@typespec/internal-build-utils": "workspace:^",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
-    "grammarkdown": "catalog:",
     "pathe": "catalog:",
     "rimraf": "catalog:",
     "source-map-support": "catalog:",

packages/eslint-plugin-typespec/package.json

@@ -46,7 +46,6 @@
     "@typescript-eslint/types": "catalog:",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "eslint": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",

packages/events/package.json

@@ -62,7 +62,6 @@
     "@typespec/tspd": "workspace:^",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vitest": "catalog:"

packages/html-program-viewer/package.json

@@ -71,7 +71,6 @@
     "@vitejs/plugin-react": "catalog:",
     "@vitest/coverage-v8": "catalog:",
     "@vitest/ui": "catalog:",
-    "c8": "catalog:",
     "rimraf": "catalog:",
     "typescript": "catalog:",
     "vite": "catalog:",

packages/http-client-js/eng/scripts/emit-e2e.js

@@ -1,10 +1,9 @@
 #!/usr/bin/env node
 /* eslint-disable no-console */
+import { select } from "@inquirer/prompts";
 import { execa } from "execa";
-import pkg from "fs-extra";
-import { copyFile, mkdir, rm } from "fs/promises";
+import { access, copyFile, mkdir, readFile, rm, stat, writeFile } from "fs/promises";
 import { globby } from "globby";
-import inquirer from "inquirer";
 import ora from "ora";
 import pLimit from "p-limit";
 import { basename, dirname, join, resolve } from "path";
@@ -13,11 +12,16 @@ import { fileURLToPath } from "url";
 import { hideBin } from "yargs/helpers";
 import yargs from "yargs/yargs";
 
-const { pathExists, stat, readFile, writeFile } = pkg;
-
 const __filename = fileURLToPath(import.meta.url);
 const __dirname = dirname(__filename);
 
+async function pathExists(path) {
+  return access(path).then(
+    () => true,
+    () => false,
+  );
+}
+
 const projectRoot = join(__dirname, "../..");
 const tspConfig = join(__dirname, "tspconfig.yaml");
 
@@ -185,18 +189,14 @@ async function processFile(file, options) {
     await writeFile(logFilePath, errorDetails, "utf8");
 
     if (interactive) {
-      const { action } = await inquirer.prompt([
-        {
-          type: "list",
-          name: "action",
-          message: `Processing failed for ${relativePath}. What would you like to do?`,
-          choices: [
-            { name: "Retry", value: "retry" },
-            { name: "Skip to next file", value: "next" },
-            { name: "Abort processing", value: "abort" },
-          ],
-        },
-      ]);
+      const action = await select({
+        message: `Processing failed for ${relativePath}. What would you like to do?`,
+        choices: [
+          { name: "Retry", value: "retry" },
+          { name: "Skip to next file", value: "next" },
+          { name: "Abort processing", value: "abort" },
+        ],
+      });
 
       if (action === "retry") {
         if (spinner) spinner.start(`Retrying: ${relativePath}`);