Bug-2003889: Show Lando try-push status instead of a blank-revision error

src/__tests__/Search/fetchRevisionFromLando.test.tsx

@@ -1,6 +1,7 @@
 import fetchMock from '@fetch-mock/jest';
 
 import App, { router } from '../../components/App';
+import { Strings } from '../../resources/Strings';
 import { render } from '../utils/test-utils';
 
 describe('Lando to commit validating', () => {
@@ -74,7 +75,7 @@ describe('Lando to commit validating', () => {
     (console.error as jest.Mock).mockClear();
   });
 
-  it('should reject', async () => {
+  it('should explain when Lando is still creating the try push', async () => {
     jest.spyOn(console, 'error').mockImplementation(() => {});
     fetchMock.get(
       'glob:https://api.lando.services.mozilla.com/*',
@@ -83,6 +84,118 @@ describe('Lando to commit validating', () => {
           ? {
               commit_id: null,
               id: 108,
+              status: 'SUBMITTED',
+            }
+          : {
+              commit_id: '6331cb86f104e2587160208d8e47d8bef8b38ffc',
+              id: 96,
+              status: 'LANDED',
+            };
+      },
+    );
+    await router.navigate(
+      '/compare-lando-results?baseLando=123&baseRepo=try&newLando=456&newRepo=try&framework=1',
+    );
+    render(<App />);
+    expect(console.error).toHaveBeenCalledWith(
+      new Error(Strings.errors.lando.pending('123', 'SUBMITTED')),
+    );
+    expect(console.error).toHaveBeenCalledTimes(1);
+    (console.error as jest.Mock).mockClear();
+  });
+
+  it('should explain when Lando failed to create the try push', async () => {
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+    fetchMock.get(
+      'glob:https://api.lando.services.mozilla.com/*',
+      ({ url }) => {
+        return url.includes('123')
+          ? {
+              commit_id: '096aa2c25fb2f031021de8c58baf9c46c052ab2e',
+              id: 108,
+              status: 'LANDED',
+            }
+          : {
+              commit_id: null,
+              error: 'Tree is closed',
+              id: 96,
+              status: 'FAILED',
+            };
+      },
+    );
+    await router.navigate(
+      '/compare-lando-results?baseLando=123&baseRepo=try&newLando=456&newRepo=try&framework=1',
+    );
+    render(<App />);
+    expect(console.error).toHaveBeenCalledWith(
+      new Error(Strings.errors.lando.failed('456', 'FAILED', 'Tree is closed')),
+    );
+    expect(console.error).toHaveBeenCalledTimes(1);
+    (console.error as jest.Mock).mockClear();
+  });
+
+  it('should explain a failed Lando try push that returned an empty commit_id', async () => {
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+    fetchMock.get('glob:https://lando.moz.tools/*', ({ url }) => {
+      return url.includes('91073')
+        ? {
+            commit_id: '',
+            error:
+              'Unexpected error while pushing to try.\nhg error in cmd: hg push -r tip ssh://hg.mozilla.org/try -f: pushing to ssh://hg.mozilla.org/try\n\nremote: Connection closed by 63.245.208.203 port 22\nabort: no suitable response from remote hg',
+            id: 91073,
+            status: 'FAILED',
+          }
+        : {
+            commit_id: '8920f830aab97b1912099621e73bd4cd1ee5fa23',
+            error: '',
+            id: 91086,
+            status: 'LANDED',
+          };
+    });
+    await router.navigate(
+      '/compare-lando-results?landoInstance=lando-prod-2025&baseLando=91073&newLando=91086&baseRepo=try&newRepo=try&framework=13',
+    );
+    render(<App />);
+    expect(console.error).toHaveBeenCalledWith(
+      new Error(
+        Strings.errors.lando.failed(
+          '91073',
+          'FAILED',
+          'Unexpected error while pushing to try.',
+        ),
+      ),
+    );
+    expect(console.error).toHaveBeenCalledTimes(1);
+    (console.error as jest.Mock).mockClear();
+  });
+
+  it('should explain when Lando landed but still has no revision', async () => {
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+    fetchMock.get('glob:https://api.lando.services.mozilla.com/*', {
+      commit_id: null,
+      id: 108,
+      status: 'LANDED',
+    });
+    await router.navigate(
+      '/compare-lando-results?baseLando=123&baseRepo=try&newLando=456&newRepo=try&framework=1',
+    );
+    render(<App />);
+    expect(console.error).toHaveBeenCalledWith(
+      new Error(Strings.errors.lando.landedWithoutRevision('123', 'LANDED')),
+    );
+    expect(console.error).toHaveBeenCalledTimes(1);
+    (console.error as jest.Mock).mockClear();
+  });
+
+  it('should explain when Treeherder has not ingested the try push yet', async () => {
+    jest.spyOn(console, 'error').mockImplementation(() => {});
+    fetchMock.get(
+      'glob:https://api.lando.services.mozilla.com/*',
+      ({ url }) => {
+        return url.includes('123')
+          ? {
+              commit_id: '096aa2c25fb2f031021de8c58baf9c46c052ab2e',
+              id: 108,
               status: 'LANDED',
             }
           : {
@@ -92,12 +205,20 @@ describe('Lando to commit validating', () => {
             };
       },
     );
+    fetchMock.get('glob:https://treeherder.mozilla.org/api/project/*/push/*', {
+      results: [],
+    });
     await router.navigate(
       '/compare-lando-results?baseLando=123&baseRepo=try&newLando=456&newRepo=try&framework=1',
     );
     render(<App />);
     expect(console.error).toHaveBeenCalledWith(
-      new Error('The parameter baseRev is missing.'),
+      new Error(
+        Strings.errors.lando.notInTreeherder(
+          '123',
+          '096aa2c25fb2f031021de8c58baf9c46c052ab2e',
+        ),
+      ),
     );
     expect(console.error).toHaveBeenCalledTimes(1);
     (console.error as jest.Mock).mockClear();

src/components/CompareResults/landoToCommitLoader.ts

@@ -1,13 +1,33 @@
 import { checkValues, getComparisonInformation } from './loader';
 import { compareView } from '../../common/constants';
 import { fetchRevisionFromLandoId, LandoInstance } from '../../logic/lando';
+import { fetchRecentRevisions } from '../../logic/treeherder';
+import { Strings } from '../../resources/Strings';
 import {
   Changeset,
   CombinedResultsItemType,
   Repository,
 } from '../../types/state';
 import { Framework, TestVersion } from '../../types/types';
 
+async function ensureTryPushExists({
+  landoId,
+  commitId,
+  repo,
+}: {
+  landoId: string;
+  commitId: string;
+  repo: Repository['name'];
+}) {
+  const pushes = await fetchRecentRevisions({
+    repository: repo,
+    hash: commitId,
+  });
+  if (!pushes.length) {
+    throw new Error(Strings.errors.lando.notInTreeherder(landoId, commitId));
+  }
+}
+
 // This function is responsible for fetching the data from the URL. It's called
 // by React Router DOM when the compare-lando-results route is requested.
 // This loader is used by ./mach try perf, and due to recent changes in
@@ -63,6 +83,16 @@ export async function loader({ request }: { request: Request }) {
     replicates: replicatesFromUrl,
     testVersion: testVersionFromUrl,
   });
+  await ensureTryPushExists({
+    landoId: baseLandoIDFromUrl,
+    commitId: baseRev,
+    repo: baseRepo,
+  });
+  await ensureTryPushExists({
+    landoId: newLandoIDFromUrl,
+    commitId: newRevs[0],
+    repo: newRepos[0],
+  });
   return await getComparisonInformation(
     baseRev,
     baseRepo,

src/logic/lando.ts

@@ -1,3 +1,4 @@
+import { Strings } from '../resources/Strings';
 import { LandoToCommit } from '../types/state';
 
 const landoInstances = {
@@ -9,6 +10,54 @@ const landoInstances = {
 
 export type LandoInstance = keyof typeof landoInstances;
 
+export type LandoRevision = LandoToCommit & { commit_id: string };
+
+const PENDING_STATUSES = new Set([
+  'submitted',
+  'in_progress',
+  'deferred',
+  'created',
+  'unknown',
+]);
+
+const FAILED_STATUSES = new Set(['failed', 'aborted', 'cancelled', 'canceled']);
+
+function hasCommitId(job: LandoToCommit): job is LandoRevision {
+  // New Lando returns "" rather than null when a job has not produced a revision.
+  return typeof job.commit_id === 'string' && job.commit_id.trim().length > 0;
+}
+
+function firstLine(text: string | undefined): string | undefined {
+  if (!text) {
+    return undefined;
+  }
+  for (const line of text.split(/\r?\n/)) {
+    const trimmed = line.trim();
+    if (trimmed) {
+      return trimmed;
+    }
+  }
+  return undefined;
+}
+
+export function messageForMissingLandoRevision(
+  landoId: string,
+  job: LandoToCommit,
+) {
+  const status = job.status?.trim() ? job.status : 'unknown';
+  const normalizedStatus = status.toLowerCase();
+
+  if (FAILED_STATUSES.has(normalizedStatus)) {
+    return Strings.errors.lando.failed(landoId, status, firstLine(job.error));
+  }
+
+  if (PENDING_STATUSES.has(normalizedStatus)) {
+    return Strings.errors.lando.pending(landoId, status);
+  }
+
+  return Strings.errors.lando.landedWithoutRevision(landoId, status);
+}
+
 async function fetchFromLando(url: string) {
   const response = await fetch(url);
   if (!response.ok) {
@@ -20,11 +69,17 @@ async function fetchFromLando(url: string) {
 }
 
 export async function fetchRevisionFromLandoId(
-  landoid: string,
+  landoId: string,
   instance: LandoInstance = 'lando-prod',
-) {
+): Promise<LandoRevision> {
   const host = landoInstances[instance] ?? landoInstances['lando-prod'];
-  const url = `https://${host}/landing_jobs/${landoid}`;
+  const url = `https://${host}/landing_jobs/${landoId}`;
   const response = await fetchFromLando(url);
-  return response.json() as Promise<LandoToCommit>;
+  const job = (await response.json()) as LandoToCommit;
+
+  if (!hasCommitId(job)) {
+    throw new Error(messageForMissingLandoRevision(landoId, job));
+  }
+
+  return job;
 }

src/resources/Strings.tsx

@@ -184,5 +184,17 @@ export const Strings = {
   },
   errors: {
     warningText: 'The search input must be at least three characters.',
+    lando: {
+      pending: (landoId: string, status: string) =>
+        `Lando has not finished creating the try push for job ${landoId} yet (status: ${status}). Please wait a few moments for the push to complete and then refresh the page.`,
+      failed: (landoId: string, status: string, detail?: string) =>
+        detail
+          ? `Lando could not create the try push for job ${landoId} (status: ${status}): ${detail}`
+          : `Lando could not create the try push for job ${landoId} (status: ${status}).`,
+      landedWithoutRevision: (landoId: string, status: string) =>
+        `Lando reports job ${landoId} as ${status}, but no Treeherder revision is available yet. Please wait a few moments and then refresh the page.`,
+      notInTreeherder: (landoId: string, revision: string) =>
+        `Lando job ${landoId} has revision ${revision}, but Treeherder does not have this try push yet. If the push exists, it will appear in a few minutes once Treeherder has processed it. If this Lando ID is from lando.moz.tools, add landoInstance=lando-prod-2025 to the URL.`,
+    },
   },
 };

src/types/state.ts

@@ -222,9 +222,10 @@ export type HashToCommit = {
 };
 
 export type LandoToCommit = {
-  commit_id: string;
-  id: string;
+  commit_id: string | null;
+  id: string | number;
   status: string;
+  error?: string;
 };
 
 export type InputType = 'base' | 'new';