fix(rca): view-report link uses canonical observability_url (correct TFA sub-tab on load)

src/tools/tfa-rca-utils/constants.ts

@@ -22,16 +22,20 @@ export function getO11yUiBaseUrl(): string {
   return appConfig.BROWSERSTACK_O11Y_UI_BASE_URL;
 }
 
+/** Query that deep-links a dashboard build URL to the AI-report TFA sub-tab. */
+export const AI_REPORT_TFA_QUERY = "tab=ai_report&subTab=tfa";
+
+/** Read a build's metadata — carries the canonical `observability_url`. */
+export const BUILD_DETAILS_PATH = "/ext/v1/builds/{buildUuid}";
+
 /**
- * TRA UI deep-link for a build's AI report (confirmed shape, 2026-07-13):
- * `<UI_BASE>/builds/<buildUuid>?tab=ai_report&subTab=aitfa` — the AI-TFA
- * sub-tab of the build's AI report. `{buildUuid}` is replaced with the
- * caller-supplied build id.
+ * UUID-form deep-link — fallback when the canonical `observability_url` can't
+ * be read. The UUID URL 302-redirects and the redirect drops the query string,
+ * so prefer the canonical URL (see `trigger-report.ts`).
  */
-export const O11Y_UI_BUILD_PATH =
-  "/builds/{buildUuid}?tab=ai_report&subTab=aitfa";
+export const O11Y_UI_BUILD_PATH = `/builds/{buildUuid}?${AI_REPORT_TFA_QUERY}`;
 
-/** Human-facing TRA UI link for one build's full report. */
+/** Human-facing TRA UI link for one build's full report (UUID fallback form). */
 export function getO11yUiBuildUrl(buildUuid: string): string {
   return (
     getO11yUiBaseUrl() +
@@ -45,7 +49,7 @@ export function getO11yUiBuildUrl(buildUuid: string): string {
  * (build page → AI report → AI TFA sub-tab).
  */
 export function getRcaViewGuidance(): string {
-  return `${getO11yUiBaseUrl()} — open the build's AI report (tab=ai_report, subTab=aitfa) to view the full RCA`;
+  return `${getO11yUiBaseUrl()} — open the build's AI report (tab=ai_report, subTab=tfa) to view the full RCA`;
 }
 
 /** Trigger (or read, when already complete) a build's Release Readiness report. */

src/tools/tfa-rca-utils/trigger-report.ts

@@ -2,6 +2,8 @@ import { apiClient } from "../../lib/apiClient.js";
 import { getBrowserStackAuth } from "../../lib/get-auth.js";
 import { BrowserStackConfig } from "../../lib/types.js";
 import {
+  AI_REPORT_TFA_QUERY,
+  BUILD_DETAILS_PATH,
   getO11yBaseUrl,
   getO11yUiBuildUrl,
   RELEASE_READINESS_TRIGGER_PATH,
@@ -76,6 +78,32 @@ function mapTriggerError(status: number, data: unknown): TriggerRcaReportError {
  * a build via the o11y external API, returning a trimmed glimpse. Stateless:
  * nothing persists between calls.
  */
+/**
+ * "View report" link = the build's canonical `observability_url` + the TFA
+ * sub-tab. The UUID form 302-redirects and drops the query, loading the wrong
+ * sub-tab; the trigger response carries no URL, so read it from build metadata
+ * and fall back to the UUID deep-link only if that read fails.
+ */
+async function resolveViewReport(
+  buildUuid: string,
+  headers: Record<string, string>,
+): Promise<string> {
+  try {
+    const url =
+      getO11yBaseUrl() +
+      BUILD_DETAILS_PATH.replace("{buildUuid}", encodeURIComponent(buildUuid));
+    const resp = await apiClient.get({ url, headers, raise_error: false });
+    const observabilityUrl =
+      resp.ok && typeof resp.data?.observability_url === "string"
+        ? resp.data.observability_url
+        : undefined;
+    if (observabilityUrl) return `${observabilityUrl}?${AI_REPORT_TFA_QUERY}`;
+  } catch {
+    // fall through to the UUID deep-link
+  }
+  return getO11yUiBuildUrl(buildUuid);
+}
+
 export async function triggerRcaReport(
   args: TriggerRcaReportArgs,
   config: BrowserStackConfig,
@@ -119,6 +147,6 @@ export async function triggerRcaReport(
     totalPrs: summary.totalPrs,
     faultyPrNumbers: summary.faultyPrNumbers,
     failureReason: summary.failureReason,
-    viewReport: getO11yUiBuildUrl(args.buildUuid),
+    viewReport: await resolveViewReport(args.buildUuid, headers),
   };
 }

tests/tools/triggerRcaReport.test.ts

@@ -36,6 +36,7 @@ const mockConfig = {
 };
 
 const post = apiClient.post as Mock;
+const get = apiClient.get as Mock;
 
 function ok(data: any, status = 200) {
   return { ok: true, status, data };
@@ -72,6 +73,10 @@ describe("triggerRcaReportTool", () => {
 
   it("success → trimmed glimpse with UI link; prs/workflows never echoed", async () => {
     post.mockResolvedValue(fullReport());
+    // Canonical dashboard URL comes from the build's observability_url.
+    get.mockResolvedValue(
+      ok({ observability_url: `${UI_BASE}/projects/P+Name/builds/bname/1` }),
+    );
 
     const result = await triggerRcaReportTool(
       { buildUuid: "b-1" },
@@ -91,7 +96,9 @@ describe("triggerRcaReportTool", () => {
     expect(payload.failureReason).toBe(
       "2 product regressions traced to PR #412",
     );
-    expect(payload.viewReport).toBe(`${UI_BASE}/builds/b-1?tab=ai_report&subTab=aitfa`);
+    expect(payload.viewReport).toBe(
+      `${UI_BASE}/projects/P+Name/builds/bname/1?tab=ai_report&subTab=tfa`,
+    );
     // Raw response is never echoed: no prs[]/workflows[] entries, no envelope.
     expect(payload.prs).toBeUndefined();
     expect(payload.workflows).toBeUndefined();
@@ -132,6 +139,8 @@ describe("triggerRcaReportTool", () => {
     post.mockResolvedValue(
       ok({ state: "running", buildUuid: "b-2", triggeredAt: "now" }),
     );
+    // Build metadata unavailable → fall back to the UUID deep-link (still subTab=tfa).
+    get.mockResolvedValue(nonOk(404));
 
     const result = await triggerRcaReportTool(
       { buildUuid: "b-2" },
@@ -140,7 +149,9 @@ describe("triggerRcaReportTool", () => {
     const payload = JSON.parse(result.content[0].text as string);
     expect(payload.state).toBe("running");
     expect(payload.verdict).toBeUndefined();
-    expect(payload.viewReport).toBe(`${UI_BASE}/builds/b-2?tab=ai_report&subTab=aitfa`);
+    expect(payload.viewReport).toBe(
+      `${UI_BASE}/builds/b-2?tab=ai_report&subTab=tfa`,
+    );
   });
 
   it("403 plan/flag fence → clear domain error", async () => {