Config-related gaps between the existing SDK libraries and the JS emitter

[kazrael2119]

Codegen gaps identified after config/ migration

After investigating the SDK-side batch PRs (#38557, #38574, #38580, #38583) and comparing with the codegen source in packages/rlc-common/src/metadata/, here are the specific gaps:

---

Gap A: test:node:esm script should be removed

• Generated file: package.json (the scripts section)
• Codegen file: packages/rlc-common/src/metadata/packageJson/buildAzureMonorepoPackage.ts (line ~201)
• Current code:

  "test:node:esm": "dev-tool run test:vitest --esm",

• Change needed: Remove this line. The vitest.esm.config.ts file no longer exists (removed by autorest.typescript#3938), so this script is dead. The node tests already exercise the ESM build via vitest.config.ts, and the browser tests cover browser-ESM via vitest.browser.config.ts.

---

Gap B: test:browser script should remove build-test step

• Generated file: package.json (the scripts section)
• Codegen file: packages/rlc-common/src/metadata/packageJson/buildAzureMonorepoPackage.ts (line ~180-181)
• Current code:

  "test:browser": "dev-tool run build-test && dev-tool run test:vitest --browser",

• Change needed: Update to:

  "test:browser": "dev-tool run test:vitest --browser",

  The new vitest.browser.config.ts (from eng/vitestconfigs/browser.config.ts) runs tests directly against source files (test/**/*.spec.ts) using Vite's browser mode. The separate build-test step is no longer needed.

---

Gap C: test script should include type-check step

• Generated file: package.json (the scripts section)
• Codegen file: packages/rlc-common/src/metadata/packageJson/buildAzureMonorepoPackage.ts (line ~202)
• Current code:

  test: "npm run test:node && npm run test:browser"

• Change needed: Update to:

  test: "tsc -b --noEmit && npm run test:node && npm run test:browser"

  The tsc -b --noEmit type-checks against the project references (the new config/ tsconfigs) before running tests, catching type errors early without emitting files.

---

Gap D: Missing config/tsconfig.lint.json generation

• Generated file: config/tsconfig.lint.json (currently NOT generated)
• Codegen file: Needs a new builder function, e.g. buildTsLintConfig() in packages/rlc-common/src/metadata/buildTsConfig.ts, and it needs to be called from packages/typespec-ts/src/index.ts alongside the other tsconfig builders.
• Expected content:

  {
    "extends": "../../../../tsconfig.json",
    "include": ["../src", "../test"]
  }

• Why: This is used by eslint.config.mjs for type-aware linting (see Gap E).

---

Gap E: eslint.config.mjs missing parserOptions block for typed linting

• Generated file: eslint.config.mjs
• Codegen file: packages/rlc-common/src/metadata/buildESLintConfig.ts (the esLintConfigEsm template)
• Current generated output:

  import azsdkEslint from "@azure/eslint-plugin-azure-sdk";
  
  export default azsdkEslint.config([
    {
      rules: { ... }
    }
  ]);

• Change needed: Update to:

  import azsdkEslint from "@azure/eslint-plugin-azure-sdk";
  
  export default [
    ...azsdkEslint.config([
      {
        rules: { ... },
      },
    ]),
    {
      files: ["src/**/*.ts", "src/**/*.mts", "test/**/*.ts"],
      languageOptions: {
        parserOptions: {
          projectService: false,
          project: "./config/tsconfig.lint.json",
        },
      },
    },
  ];

  This explicitly points typescript-eslint to the dedicated lint tsconfig and disables automatic projectService detection, which is required for type-aware rules to work with the new config/ directory structure. (This pairs with Gap D — both are needed together.)

---

Gap F: Copyright header missing from vitest configs

• Generated file: vitest.config.ts and vitest.browser.config.ts
• Codegen file: packages/rlc-common/src/metadata/buildVitestConfig.ts
• Change needed: Add the standard copyright header to output:

  // Copyright (c) Microsoft Corporation.
  // Licensed under the MIT License.

---

Gap G: Stale vitest.esm.config.ts not cleaned up on regeneration

• Generated file: N/A (it's a file that should be deleted)
• Codegen file: packages/typespec-ts/src/index.ts (the update/regeneration flow around line 611+)
• Change needed: When regenerating an existing package (the shouldGenerateMetadata / update path), the codegen should delete vitest.esm.config.ts if it exists, since it is no longer needed.

---

Priority summary

Gap	Impact	Notes
A	High	Every newly generated package gets a broken test:node:esm script
B	High	build-test step is unnecessary and slows down browser tests
C	High	Missing type-check means test script doesn't catch type errors
D	High	Eslint typed linting fails without this file
E	High	Eslint can't resolve types for type-aware rules
F	Low	Cosmetic, but inconsistent with SDK convention
G	Medium	Only affects regeneration of existing packages that had the old config

[JialinHuang803]

Hi @jeremymeng, we found the gaps above between the emitter and the sdk libraries when re-generating sdk code after Azure/azure-sdk-for-js#38557 was checked in, and we are trying to fix them. Could you kindly help confirm if the changes are expected? Thank you!

[jeremymeng]

Agree that we need to fill the gap A, B, C, D, F

Gap D: Missing config/tsconfig.lint.json generation

Is the generaged package.json has "lint" command of "echo skipped". If linting is skipped then tsconfig.lint.json and eslint.config.mjs are not necessary. Otherwise yes we need D and E

I also remember seeing Gap H which got removed? I think we also want the exports for subpaths in each package's warp.config.yml. My PR might have removed some. I hope re-generation will bring them back.