fix(http-client-js): allow none encoding on bytes without unknown-encoding diagnostic by Roxen-AS · Pull Request #12371 · microsoft/typespec

Akash Sarangi (Roxen-AS) · 2026-10-23T02:00:04Z

Description

When a bytes body is used with a binary content type (such as application/octet-stream), the compiler sets the default byte encoding to "none". However, @typespec/http-client-js's scalar-transform.tsx only explicitly handled "base64" and "base64url", falling through to emit an unknown-encoding warning for "none".

This PR:

Handles case "none": return passthroughTransformer(itemRef); in both toTransport and toApplication byte transforms in scalar-transform.tsx.
Adds unit test coverage verifying that an operation with a bytes body and binary content type emits cleanly without any unknown-encoding diagnostics.
Adds a Chronus changelog entry.

…oding diagnostic (microsoft#12356) Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

azure-pipelines · 2026-10-23T02:00:32Z

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Copilot

🟡 Changes recommended

The unsupported-encoding test does not trigger its expected diagnostic, and response-side warning regression coverage is missing.

2 open issues

What changed in this PR

Fixes #12356 by treating "none" as a supported byte encoding in the JavaScript HTTP client emitter, avoiding warnings for raw binary bodies.

Changes:

Adds passthrough handling for byte serialization and deserialization.
Adds tests for binary-body diagnostics and unsupported encodings.
Adds a Chronus fix entry.

File	Description
`packages/http-client-js/test/bytes-none-encoding.test.ts`	Adds encoding diagnostic tests.
`packages/http-client-js/src/components/transforms/scalar-transform.tsx`	Handles `"none"` encoding in both transform directions.
`.chronus/changes/fix-http-client-js-bytes-none-encoding.md`	Documents the warning fix.

_{Review effort: Balanced}

…lar for unsupported encoding Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot

🟢 Approval recommended

The focused change preserves byte handling and covers both transformation directions, with no unresolved blocking issues from static review; tests were not executed.

1 open issue

Tests do not assert diagnostics for the toApplication branch

1 resolved since last review

Property-level encoding bypasses the byte transformer

_{Review effort: Balanced}

…body transform Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot

🟢 Approval recommended

The narrow fix preserves byte passthrough behavior, covers both affected directions, and has no identified blocking issues.

No open issues 🎉

1 resolved since last review

Tests do not assert diagnostics for the toApplication branch

_{Review effort: Balanced}

pkg-pr-new · 2026-10-23T20:21:20Z

Open in StackBlitz

npm i https://pkg.pr.new/microsoft/typespec/@typespec/http-client-js@12371

commit: 7e6e3b4

github-actions · 2026-10-23T20:23:33Z

All changed packages have been documented.

✅ @typespec/http-client-js

Show changes

`@typespec/http-client-js` - fix ✏️

Prevent reporting spurious unknown-encoding warnings for raw bytes body with none encoding (e.g. binary content types such as application/octet-stream).

Jeff Fisher (xirzec)

Overall, a good change, but I'd appreciate the commented cleanups before merging.

Jeff Fisher (xirzec) · 2026-10-23T20:26:10Z

+    `;
+    const [outputs, diagnostics] = await emitWithDiagnostics(code);
+    expect(diagnostics.length).toBeGreaterThan(0);
+    expect(diagnostics.some((d) => d.code === "@typespec/http-client-js/unknown-encoding")).toBe(true);


please follow the repo convention to use expectDiagnostics instead of rolling your own, e.g.

Suggested change

expect(diagnostics.some((d) => d.code === "@typespec/http-client-js/unknown-encoding")).toBe(true);

expectDiagnostics(diagnostics, [

{ code: "@typespec/http-client-js/unknown-encoding", severity: "warning" },

{ code: "@typespec/http-client-js/unknown-encoding", severity: "warning" },

]);

Updated to use \expectDiagnostics\ per convention in commit 029981e. Thanks!

Jeff Fisher (xirzec) · 2026-10-23T20:26:27Z

+    `;
+    const [outputs, diagnostics] = await emitWithDiagnostics(code);
+    expect(diagnostics.length).toBeGreaterThan(0);
+    expect(diagnostics.some((d) => d.code === "@typespec/http-client-js/unknown-encoding")).toBe(true);


same as above

Suggested change

expect(diagnostics.some((d) => d.code === "@typespec/http-client-js/unknown-encoding")).toBe(true);

expectDiagnostics(diagnostics, {

code: "@typespec/http-client-js/unknown-encoding",

severity: "warning",

});

Updated to use \expectDiagnostics\ in commit 029981e. Thanks!

Jeff Fisher (xirzec) · 2026-10-23T20:28:26Z

+        @body body: bytes,
+      ): void;
+    `;
+    const [outputs, diagnostics] = await emitWithDiagnostics(code);


you can reuse the emit helper from test-host.ts for this

Updated both clean request and response tests to reuse the \emit\ helper in commit 029981e. Thanks!

…w feedback Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot

🟢 Approval recommended

The focused fix preserves byte passthrough behavior, covers both transformation directions, and retains warnings for unsupported encodings.

No open issues 🎉

_{Review effort: Balanced}

fix(http-client-js): allow none encoding on bytes without unknown-enc…

4702456

…oding diagnostic (microsoft#12356) Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot AI balanced review requested due to automatic review settings October 23, 2026 02:00

Akash Sarangi (Roxen-AS) requested review from Mary Gao (MaryGao), catalinaperalta, iscai-msft, Maor Leger (maorleger), Mark Cowlishaw (markcowl), Qiaoqiao Zhang (qiaozha), Timothee Guerin (timotheeguerin) and Jeff Fisher (xirzec) as code owners October 23, 2026 02:00

microsoft-github-policy-service Bot added the emitter:client:js Issue for the JS client emitter: @typespec/http-client-js label Oct 23, 2026

Copilot started reviewing on behalf of Akash Sarangi (Roxen-AS) October 23, 2026 02:01

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Copilot AI reviewed Oct 23, 2026

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Comment thread packages/http-client-js/test/bytes-none-encoding.test.ts

Comment thread packages/http-client-js/src/components/transforms/scalar-transform.tsx

test(http-client-js): add response-side byte test and use derived sca…

2e08dbb

…lar for unsupported encoding Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot AI balanced review requested due to automatic review settings October 23, 2026 02:36

Copilot started reviewing on behalf of Akash Sarangi (Roxen-AS) October 23, 2026 02:37

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Copilot AI reviewed Oct 23, 2026

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test(http-client-js): assert unknown-encoding diagnostic on response …

7e6e3b4

…body transform Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot AI balanced review requested due to automatic review settings October 23, 2026 02:58

Copilot started reviewing on behalf of Akash Sarangi (Roxen-AS) October 23, 2026 02:58

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Copilot AI reviewed Oct 23, 2026

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Jeff Fisher (xirzec) approved these changes Oct 23, 2026

View reviewed changes

test(http-client-js): use expectDiagnostics and emit helper per revie…

029981e

…w feedback Signed-off-by: Roxen-AS <akash.arjun12@gmail.com>

Copilot AI balanced review requested due to automatic review settings October 24, 2026 05:55

Copilot started reviewing on behalf of Akash Sarangi (Roxen-AS) October 24, 2026 05:56

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Copilot AI reviewed Oct 24, 2026

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-    expect(diagnostics.some((d) => d.code === "@typespec/http-client-js/unknown-encoding")).toBe(true);
+    expectDiagnostics(diagnostics, [
+  { code: "@typespec/http-client-js/unknown-encoding", severity: "warning" },
+  { code: "@typespec/http-client-js/unknown-encoding", severity: "warning" },
+]);

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Akash Sarangi (Roxen-AS) commented Oct 23, 2026

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pkg-pr-new Bot commented Oct 23, 2026

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github-actions Bot commented Oct 23, 2026

@typespec/http-client-js - fix ✏️

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`@typespec/http-client-js` - fix ✏️