fix(mrkdwn): convert Slack angle-bracket links to Markdown for markdown block

packages/junior/src/chat/slack/mrkdwn.ts

@@ -58,6 +58,25 @@ export function ensureBlockSpacing(text: string): string {
 export function renderSlackMrkdwn(text: string): string {
   let normalized = text.replace(/\r\n?/g, "\n").replace(/[ \t]+$/gm, "");
   normalized = ensureBlockSpacing(normalized);
+  // The body is sent as a Slack `markdown` block, which expects standard
+  // Markdown links ([label](url)), not Slack mrkdwn angle-bracket syntax
+  // (<URL> / <URL|label>). Convert to explicit Markdown links so the block
+  // renders them correctly and bold markers (**) can never collide with the
+  // angle brackets and corrupt the URL.
+  //
+  // Pass 1: repair malformed bold-wrapped angle autolinks produced by the
+  // model: **<https://url**> → [https://url](https://url)
+  normalized = normalized.replace(
+    /\*\*<(https?:\/\/[^*>\s]+)\*\*>/g,
+    "[$1]($1)",
+  );
+  // Pass 2: Slack labeled links → Markdown: <https://url|label> → [label](https://url)
+  normalized = normalized.replace(
+    /<(https?:\/\/[^|>\s]+)\|([^>]+)>/g,
+    "[$2]($1)",
+  );
+  // Pass 3: remaining angle autolinks → explicit Markdown links: <https://url> → [https://url](https://url)
+  normalized = normalized.replace(/<(https?:\/\/[^>\s]+)>/g, "[$1]($1)");
   return normalized.replace(/\n{3,}/g, "\n\n").trim();
 }
 

packages/junior/tests/unit/misc/output.test.ts

@@ -15,6 +15,52 @@ describe("renderSlackMrkdwn", () => {
       "one\n\n- item a\n- item b\n\ntwo",
     );
   });
+
+  it("converts Slack angle-bracket URL to explicit Markdown link", () => {
+    expect(
+      renderSlackMrkdwn("See <https://example.com> for details."),
+    ).toBe("See [https://example.com](https://example.com) for details.");
+  });
+
+  it("converts Slack labeled links to Markdown format", () => {
+    expect(
+      renderSlackMrkdwn("<https://github.com/org/repo/pull/1|PR #1>"),
+    ).toBe("[PR #1](https://github.com/org/repo/pull/1)");
+  });
+
+  it("resolves bold+angle-bracket collision that broke GitHub PR links", () => {
+    // The model generated **<https://url**> — closing ** absorbed inside the
+    // angle brackets. Pass 1 catches this and converts to [url](url).
+    expect(
+      renderSlackMrkdwn(
+        "**<https://github.com/getsentry/sentry/pull/116765**>",
+      ),
+    ).toBe(
+      "[https://github.com/getsentry/sentry/pull/116765](https://github.com/getsentry/sentry/pull/116765)",
+    );
+  });
+
+  it("converts multiple angle-bracket URLs in one message", () => {
+    expect(
+      renderSlackMrkdwn(
+        "PR1: <https://github.com/org/repo/pull/1> and PR2: <https://github.com/org/repo/pull/2>",
+      ),
+    ).toBe(
+      "PR1: [https://github.com/org/repo/pull/1](https://github.com/org/repo/pull/1) and PR2: [https://github.com/org/repo/pull/2](https://github.com/org/repo/pull/2)",
+    );
+  });
+
+  it("leaves Markdown links unchanged", () => {
+    expect(
+      renderSlackMrkdwn("**[PR #123](https://github.com/org/repo/pull/123)**"),
+    ).toBe("**[PR #123](https://github.com/org/repo/pull/123)**");
+  });
+
+  it("leaves plain bold text unchanged", () => {
+    expect(renderSlackMrkdwn("**Root cause** is here.")).toBe(
+      "**Root cause** is here.",
+    );
+  });
 });
 
 describe("buildSlackOutputMessage", () => {