Harden twoslash config against silent regressions by slang25 · Pull Request #740 · microsoft/aspire.dev

slang25 · 2026-04-21T17:37:44Z

Two small defensive changes in ec.config.mjs, layered on top of #741.

Changes

Throw instead of warn when src/data/twoslash/aspire.d.ts is missing. Since Fix twoslash in AppHostBuilder; source-control twoslash .d.ts bundle #741 source-controls the bundle, a missing file means the working tree is corrupted — not a normal path. Catching that at build time beats silently shipping samples that can't resolve ./.modules/aspire.js.
Flip noErrorValidation to false so unannotated TS errors fail the build rather than rendering as squigglies in the shipped HTML. Samples that deliberately illustrate a compiler error can opt in with // @errors: <codes>; otherwise an error means the sample (or the generated SDK shape) is wrong and should be fixed, not shown to readers.

Originally this PR also carried a frontend.esproj publish-time MSBuild target. That fix is no longer needed: #741 source-controls the generated bundle, so dotnet publish no longer depends on a pre-build type-generation step. Dropped it.

Test plan

Full pnpm build:skip-search passes with noErrorValidation: false — no existing sample has an unannotated TS error
Generated HTML in dist/ has zero Cannot find module / twoslash-error markers
Deleting src/data/twoslash/aspire.d.ts and re-importing ec.config.mjs throws; restoring it loads cleanly
pnpm test:unit:twoslash-types passes

🤖 Generated with Claude Code

Copilot

Pull request overview

This PR prevents TypeScript twoslash type-bundle regressions from silently shipping to the live docs site by (1) failing the Astro build when the generated .twoslash-types/aspire.d.ts bundle is missing and (2) ensuring the frontend dist/ (and twoslash types) are produced during dotnet publish of the StaticHost.

Changes:

Make ec.config.mjs throw (instead of warn) when .twoslash-types/aspire.d.ts is missing to turn a prod-only failure into a build-time failure.
Add a publish-time MSBuild target in frontend.esproj to run pnpm install --frozen-lockfile and pnpm run build before publishing.

Reviewed changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated 1 comment.

File	Description
src/frontend/frontend.esproj	Adds a publish hook intended to ensure `pnpm install` + `pnpm build` run during `dotnet publish`.
src/frontend/ec.config.mjs	Fails fast if the twoslash types bundle is missing and always injects the types into twoslash’s VFS.

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Per Copilot review on PR microsoft#740: BeforeTargets="Publish" runs after the Publish target's dependencies, so file enumeration and copy already saw a stale dist/ before our pnpm build ran. Switch to two earlier hooks: - Inject BuildFrontendForPublish into PublishDependsOn so it's the first dep of Publish (idiomatic .NET SDK pattern). - BeforeTargets="PrepareForPublish;ComputeFilesToPublish" as a backstop in case the JS SDK invokes those outside the PublishDependsOn flow. Both fire before any publish-time file collection, ensuring dist/ is fresh when the SDK packages the StaticHost.

@errors

Two small defensive changes on top of microsoft#741: - Throw instead of warn when src/data/twoslash/aspire.d.ts is missing. Since microsoft#741 source-controls the bundle, a missing file means the tree is corrupted — catching that at build time beats silently shipping samples that can't resolve `./.modules/aspire.js`. - Flip noErrorValidation to false so unannotated TS errors fail the build rather than rendering as squigglies in the shipped HTML. Samples that deliberately illustrate a compiler error can opt in with `// @errors: <codes>`; otherwise an error means the sample (or the generated SDK shape) is wrong and should be fixed, not shown to readers. Verified with a full build: zero unannotated errors across the current docs.

Copilot

Pull request overview

Copilot reviewed 1 out of 1 changed files in this pull request and generated 4 comments.

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Copilot · 2026-04-21T19:26:02Z

+if (!existsSync(ASPIRE_TYPES_PATH)) {
+  throw new Error(
+    `[ec] src/data/twoslash/aspire.d.ts not found at ${ASPIRE_TYPES_PATH}. ` +
+      'Run `pnpm twoslash-types` to regenerate it from src/data/ts-modules.'
+  );
 }
+const aspireTypes = readFileSync(ASPIRE_TYPES_PATH, 'utf8');


This is a check-then-read pattern (TOCTOU). It’s more robust to read the file directly and throw a tailored error if it fails (e.g., wrap readFileSync in a try/catch). This avoids rare edge cases where the file is deleted/moved between existsSync and readFileSync, and keeps the failure mode consistent.

Copilot · 2026-04-21T19:26:02Z

+  );
 }
+const aspireTypes = readFileSync(ASPIRE_TYPES_PATH, 'utf8');



With the new behavior, an empty (or whitespace-only) aspire.d.ts will still pass and will populate .modules/aspire.ts with empty content, which can re-introduce the ‘silent regression’ this PR is trying to prevent (imports resolve, but types effectively disappear). Consider validating aspireTypes.trim().length > 0 and throwing with a clear message if it’s empty.

Suggested change

if (aspireTypes.trim().length === 0) {

throw new Error(

`[ec] src/data/twoslash/aspire.d.ts is empty at ${ASPIRE_TYPES_PATH}. ` +

'Run `pnpm twoslash-types` to regenerate it from src/data/ts-modules.'

);

}

Copilot · 2026-04-21T19:26:02Z

        // are declared at `.modules/aspire.ts` so docs samples that import
        // `'./.modules/aspire.js'` resolve against the real API surface.
-        extraFiles: aspireTypes ? { '.modules/aspire.ts': aspireTypes } : {},
+        extraFiles: { '.modules/aspire.ts': aspireTypes },


With the new behavior, an empty (or whitespace-only) aspire.d.ts will still pass and will populate .modules/aspire.ts with empty content, which can re-introduce the ‘silent regression’ this PR is trying to prevent (imports resolve, but types effectively disappear). Consider validating aspireTypes.trim().length > 0 and throwing with a clear message if it’s empty.

Copilot · 2026-04-21T19:26:03Z

+// shipping samples that can't resolve `./.modules/aspire.js`.
+if (!existsSync(ASPIRE_TYPES_PATH)) {
+  throw new Error(
+    `[ec] src/data/twoslash/aspire.d.ts not found at ${ASPIRE_TYPES_PATH}. ` +


The error message includes an absolute path, which can leak runner/workspace paths into public CI logs. Consider switching to a relative path in the message (e.g., relative to process.cwd()), while still keeping enough context to debug locally.

IEvangelist · 2026-04-22T15:26:28Z

Hey @slang25 is this still needed?

Copilot AI review requested due to automatic review settings April 21, 2026 17:37

slang25 requested a review from IEvangelist as a code owner April 21, 2026 17:37

Copilot AI reviewed Apr 21, 2026

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Comment thread src/frontend/frontend.esproj Outdated

IEvangelist reviewed Apr 21, 2026

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Comment thread src/frontend/frontend.esproj

slang25 force-pushed the slang25/twoslash-types-deploy-safety branch from b2bacf2 to 5eecbb6 Compare April 21, 2026 19:17

slang25 changed the title ~~Fix missing twoslash types silently shipping to production~~ Harden twoslash config against silent regressions Apr 21, 2026

slang25 requested a review from Copilot April 21, 2026 19:19

Copilot AI reviewed Apr 21, 2026

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IEvangelist approved these changes Apr 21, 2026

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Copilot started reviewing on behalf of slang25 April 21, 2026 19:29 View session

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Harden twoslash config against silent regressions#740

Harden twoslash config against silent regressions#740
slang25 wants to merge 1 commit intomicrosoft:mainfrom
slang25:slang25/twoslash-types-deploy-safety

slang25 commented Apr 21, 2026 •

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slang25 commented Apr 21, 2026 •

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