fix(source-control): date Azure PRs by recent activity

packages/source-control-azure-devops/src/server/AzureDevOpsPullRequestCli.test.ts

@@ -172,6 +172,25 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
             output(json({ ...pullRequestRow, lastMergeSourceCommit: { commitId: previousHead } })),
           ),
         )
+        // Azure's own row dates it by creation; the system thread its last push added is newer.
+        .mockReturnValueOnce(
+          Effect.succeed(
+            output(
+              json({
+                value: [
+                  {
+                    id: 1,
+                    publishedDate: "2026-07-10T10:00:00Z",
+                    lastUpdatedDate: "2026-07-10T12:30:00.123+02:00",
+                    comments: [
+                      { id: 1, commentType: "system", publishedDate: "2026-07-10T10:00:00Z" },
+                    ],
+                  },
+                ],
+              }),
+            ),
+          ),
+        )
         .mockReturnValueOnce(
           Effect.succeed(
             output(
@@ -199,8 +218,10 @@ layer("AzureDevOpsPullRequestCli.layer", (it) => {
       });
 
       expect(detail.headSha).toBe(latestHead);
-      expect(argsOfCall(2)).toContain("iterationId=2");
-      expect(mockedExecute).toHaveBeenCalledTimes(4);
+      expect(detail.updatedAt).toBe("2026-07-10T10:30:00.123Z");
+      expect(argsOfCall(1)).toContain("pullRequestThreads");
+      expect(argsOfCall(3)).toContain("iterationId=2");
+      expect(mockedExecute).toHaveBeenCalledTimes(5);
     }),
   );
 

packages/source-control-azure-devops/src/server/AzureDevOpsPullRequestCli.ts

@@ -24,6 +24,7 @@ import {
   decodePolicyChecksJson,
   decodePullRequestJson,
   decodePullRequestListJson,
+  decodeThreadActivityJson,
   decodeThreadsJson,
   decodeViewerJson,
   type AzureDevOpsChangeEntry,
@@ -186,6 +187,13 @@ export class AzureDevOpsPullRequestCli extends Context.Service<
       readonly number: number;
     }) => Effect.Effect<ReadonlyArray<PullRequestComment>, AzureDevOpsPullRequestCliError>;
 
+    /** The newest thread or comment time, which is when anything last happened on the pull request. */
+    readonly readActivityAt: (input: {
+      readonly cwd: string;
+      readonly location: AzureDevOpsRepositoryLocation;
+      readonly number: number;
+    }) => Effect.Effect<string | null, AzureDevOpsPullRequestCliError>;
+
     readonly listIterations: (input: {
       readonly cwd: string;
       readonly location: AzureDevOpsRepositoryLocation;
@@ -628,6 +636,17 @@ export const make = Effect.gen(function* () {
       });
     }),
 
+    readActivityAt: Effect.fn("AzureDevOpsPullRequestCli.readActivityAt")(function (input) {
+      return invoke({
+        cwd: input.cwd,
+        operation: "listThreads",
+        resource: "pullRequestThreads",
+        routeParameters: pullRequestRoute(input),
+        maxOutputBytes: REVIEW_HISTORY_MAX_OUTPUT_BYTES,
+        decode: decodeThreadActivityJson,
+      });
+    }),
+
     listIterations: Effect.fn("AzureDevOpsPullRequestCli.listIterations")(function (input) {
       return invoke({
         cwd: input.cwd,

packages/source-control-azure-devops/src/server/AzureDevOpsPullRequestProvider.test.ts

@@ -76,6 +76,7 @@ const readSlice = (input: {
         Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
           ...NO_BLOBS,
           getPullRequest: () => Effect.succeed(PULL_REQUEST),
+          readActivityAt: () => Effect.succeed(null),
           listIterations: () => Effect.succeed([ITERATION]),
           listIterationChanges: () =>
             Effect.succeed({
@@ -128,13 +129,57 @@ function patchedPaths(patch: string): ReadonlyArray<string> {
   );
 }
 
+it.effect("dates an open pull request by its newest thread and keeps its own date otherwise", () =>
+  Effect.gen(function* () {
+    const activity: Array<
+      Effect.Effect<string | null, AzureDevOpsPullRequestCli.AzureDevOpsPullRequestReadError>
+    > = [
+      Effect.succeed("2026-07-05T08:00:00.000Z"),
+      Effect.succeed("2026-07-05T08:00:00.000Z"),
+      Effect.fail(
+        new AzureDevOpsPullRequestCli.AzureDevOpsPullRequestReadError({
+          command: "az",
+          cwd: "/w",
+          operation: "listThreads",
+          cause: "unavailable",
+        }),
+      ),
+    ];
+    let shown: typeof PULL_REQUEST | (Omit<typeof PULL_REQUEST, "state"> & { state: "merged" }) =
+      PULL_REQUEST;
+    const provider = yield* make.pipe(
+      Effect.provide(
+        Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
+          getPullRequest: () => Effect.succeed(shown),
+          runPullRequestAction: () => Effect.succeed(shown),
+          listPolicyChecks: () => Effect.succeed([]),
+          readActivityAt: () => activity.shift() ?? Effect.die("a closed pull request was read"),
+        }),
+      ),
+    );
+    const input = { cwd: "/w", repository: "acme/web", host: "dev.azure.com", number: 7 };
+    const summaryDate = provider.getChangeRequestSummary!(input).pipe(
+      Effect.map((summary) => summary.updatedAt),
+    );
+
+    expect(yield* summaryDate).toBe("2026-07-05T08:00:00.000Z");
+    // Clients drop a reply dated before the summary they show.
+    const reply = yield* provider.runAction({ ...input, action: "ready" });
+    expect(reply?.updatedAt).toBe("2026-07-05T08:00:00.000Z");
+    expect(yield* summaryDate).toBe(PULL_REQUEST.updatedAt);
+    shown = { ...PULL_REQUEST, state: "merged" };
+    expect(yield* summaryDate).toBe(PULL_REQUEST.updatedAt);
+  }),
+);
+
 describe("getChangeRequest", () => {
   it.effect("preserves the newest head when file counting fails", () =>
     Effect.gen(function* () {
       const provider = yield* make.pipe(
         Effect.provide(
           Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
             getPullRequest: () => Effect.succeed(PULL_REQUEST),
+            readActivityAt: () => Effect.succeed(null),
             listPolicyChecks: () => Effect.succeed([]),
             listIterations: () =>
               Effect.succeed([ITERATION, { ...ITERATION, id: 4, headCommit: "new-head" }]),
@@ -170,6 +215,7 @@ describe("getChangeRequest", () => {
           Effect.provide(
             Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
               getPullRequest: () => Effect.succeed(PULL_REQUEST),
+              readActivityAt: () => Effect.succeed(null),
               listPolicyChecks: () => Effect.succeed([]),
               listIterations: () =>
                 state === "missing"
@@ -226,6 +272,7 @@ describe("policy checks", () => {
       Effect.provide(
         Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
           getPullRequest: () => Effect.succeed(pullRequest),
+          readActivityAt: () => Effect.succeed(null),
           listIterations: () => Effect.succeed([ITERATION]),
           listIterationChanges: () => Effect.succeed({ changes: [], truncated: false }),
           listPolicyChecks,
@@ -273,6 +320,7 @@ describe("getDiff reads", () => {
           Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
             ...NO_BLOBS,
             getPullRequest: () => Effect.succeed(PULL_REQUEST),
+            readActivityAt: () => Effect.succeed(null),
             listIterations: () => Effect.succeed([ITERATION]),
             listIterationChanges: () =>
               Effect.succeed({ changes: paths.map((path) => change(path)), truncated: false }),
@@ -318,6 +366,7 @@ describe("getDiff reads", () => {
         Effect.provide(
           Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
             getPullRequest: () => Effect.succeed(PULL_REQUEST),
+            readActivityAt: () => Effect.succeed(null),
             listIterations: () => Effect.succeed([ITERATION]),
             listIterationChanges: () => Effect.succeed({ changes, truncated: false }),
             readBlobs: (input) =>
@@ -386,6 +435,7 @@ describe("getDiff reads", () => {
         Effect.provide(
           Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
             getPullRequest: () => Effect.succeed(PULL_REQUEST),
+            readActivityAt: () => Effect.succeed(null),
             listIterations: () => Effect.succeed([ITERATION]),
             listIterationChanges: () =>
               Effect.succeed({
@@ -440,6 +490,7 @@ describe("getDiff reads", () => {
           Layer.mock(AzureDevOpsPullRequestCli.AzureDevOpsPullRequestCli)({
             ...NO_BLOBS,
             getPullRequest: () => Effect.succeed(PULL_REQUEST),
+            readActivityAt: () => Effect.succeed(null),
             listIterations: () => Effect.sync(() => ((iterationReads += 1), [ITERATION])),
             listIterationChanges: () =>
               Effect.sync(() => {

packages/source-control-azure-devops/src/server/AzureDevOpsPullRequestProvider.ts

@@ -27,12 +27,13 @@ import {
   type ProviderDiffSlice,
   type PullRequestProviderApi,
 } from "@t3tools/source-control-core/server/PullRequestProvider";
-import type {
-  AzureDevOpsChangeEntry,
-  AzureDevOpsItemContent,
-  AzureDevOpsIteration,
-  AzureDevOpsPullRequest,
-  AzureDevOpsRepositoryLocation,
+import {
+  latestAzureDevOpsTime,
+  type AzureDevOpsChangeEntry,
+  type AzureDevOpsItemContent,
+  type AzureDevOpsIteration,
+  type AzureDevOpsPullRequest,
+  type AzureDevOpsRepositoryLocation,
 } from "./azureDevOpsPullRequestJson.ts";
 import { definition } from "../shared/definition.ts";
 
@@ -227,6 +228,23 @@ export const make = Effect.gen(function* () {
       isDraft: pullRequest.isDraft,
     });
 
+  /**
+   * Azure's own rows date an open pull request by its creation, so a read of one pull request is
+   * dated by its newest thread instead. A failed read keeps the row's own date.
+   */
+  const withActivity = (input: { readonly cwd: string }, pullRequest: AzureDevOpsPullRequest) => {
+    const location = pullRequest.location;
+    if (pullRequest.state !== "open" || location === null) return Effect.succeed(pullRequest);
+    return cli.readActivityAt({ cwd: input.cwd, location, number: pullRequest.number }).pipe(
+      Effect.map((activityAt) => ({
+        ...pullRequest,
+        updatedAt:
+          latestAzureDevOpsTime([pullRequest.updatedAt, activityAt]) ?? pullRequest.updatedAt,
+      })),
+      Effect.orElseSucceed(() => pullRequest),
+    );
+  };
+
   /** A later slice names its iteration, which the list it was cut from already holds. */
   const diffScope = Effect.fn("AzureDevOpsPullRequestProvider.diffScope")(function* (input: {
     readonly cwd: string;
@@ -388,7 +406,9 @@ export const make = Effect.gen(function* () {
 
     getChangeRequestSummary: Effect.fn("AzureDevOpsPullRequestProvider.getChangeRequestSummary")(
       function* (input) {
-        const pullRequest = yield* cli.getPullRequest({ cwd: input.cwd, number: input.number });
+        const pullRequest = yield* cli
+          .getPullRequest({ cwd: input.cwd, number: input.number })
+          .pipe(Effect.flatMap((read) => withActivity(input, read)));
         // Undefined keeps the last known state; null would claim no checks exist.
         const checksState = yield* readChecks(input, pullRequest).pipe(
           Effect.map((checks) => rollupCheckStatuses(checks.map((check) => check.status))),
@@ -404,7 +424,9 @@ export const make = Effect.gen(function* () {
 
     getChangeRequest: Effect.fn("AzureDevOpsPullRequestProvider.getChangeRequest")(
       function* (input) {
-        const pullRequest = yield* cli.getPullRequest({ cwd: input.cwd, number: input.number });
+        const pullRequest = yield* cli
+          .getPullRequest({ cwd: input.cwd, number: input.number })
+          .pipe(Effect.flatMap((read) => withActivity(input, read)));
         const location = pullRequest.location;
         const iterations =
           location === null
@@ -672,15 +694,19 @@ export const make = Effect.gen(function* () {
         })
         .pipe(
           Effect.mapError(fail("runAction")),
-          Effect.map(
-            (pullRequest) =>
-              pullRequest && {
-                ...toSummary(pullRequest),
-                autoMergeEnabled: pullRequest.autoMergeEnabled,
-                ...(pullRequest.autoMergeMethod === undefined
-                  ? {}
-                  : { autoMergeMethod: pullRequest.autoMergeMethod }),
-              },
+          // Clients drop a reply dated before the summary they show, so it is dated the same way.
+          Effect.flatMap((reply) =>
+            reply
+              ? withActivity(input, reply).pipe(
+                  Effect.map((pullRequest) => ({
+                    ...toSummary(pullRequest),
+                    autoMergeEnabled: pullRequest.autoMergeEnabled,
+                    ...(pullRequest.autoMergeMethod === undefined
+                      ? {}
+                      : { autoMergeMethod: pullRequest.autoMergeMethod }),
+                  })),
+                )
+              : Effect.void,
           ),
         ),
 

packages/source-control-azure-devops/src/server/azureDevOpsPullRequestJson.ts

@@ -3,7 +3,9 @@ import {
   normalizeRefName,
 } from "@t3tools/source-control-core/server/pullRequestUtils";
 import * as Cause from "effect/Cause";
+import * as DateTime from "effect/DateTime";
 import * as Exit from "effect/Exit";
+import * as Option from "effect/Option";
 import * as Result from "effect/Result";
 import * as Schema from "effect/Schema";
 import type {
@@ -75,6 +77,8 @@ const RawPullRequestSchema = Schema.Struct({
 const RawThreadSchema = Schema.Struct({
   id: Schema.Int,
   isDeleted: Schema.optional(Schema.NullOr(Schema.Boolean)),
+  publishedDate: Schema.optional(Schema.NullOr(Schema.String)),
+  lastUpdatedDate: Schema.optional(Schema.NullOr(Schema.String)),
   threadContext: Schema.optional(
     Schema.NullOr(Schema.Struct({ filePath: Schema.optional(Schema.NullOr(Schema.String)) })),
   ),
@@ -86,6 +90,7 @@ const RawThreadSchema = Schema.Struct({
           content: Schema.optional(Schema.NullOr(Schema.String)),
           author: Schema.optional(Schema.NullOr(RawIdentitySchema)),
           publishedDate: Schema.optional(Schema.NullOr(Schema.String)),
+          lastUpdatedDate: Schema.optional(Schema.NullOr(Schema.String)),
           isDeleted: Schema.optional(Schema.NullOr(Schema.Boolean)),
           commentType: Schema.optional(Schema.NullOr(Schema.String)),
         }),
@@ -456,6 +461,38 @@ export function decodePolicyChecksJson(
   });
 }
 
+/** The newest of Azure's timestamps, which mix offsets and precisions; unreadable ones are skipped. */
+export function latestAzureDevOpsTime(values: Iterable<string | null | undefined>): string | null {
+  let latest: DateTime.Utc | null = null;
+  for (const value of values) {
+    const at = DateTime.make(value?.trim() ?? "");
+    if (Option.isSome(at) && (latest === null || DateTime.isGreaterThan(at.value, latest))) {
+      latest = at.value;
+    }
+  }
+  return latest === null ? null : DateTime.formatIso(latest);
+}
+
+/**
+ * When the pull request's conversation last moved. Azure keeps no last-updated time on a pull
+ * request, but it adds a system thread for each push, vote and state change, so every thread counts.
+ */
+export function decodeThreadActivityJson(raw: string): Result.Result<string | null, DecodeFailure> {
+  const decoded = decodeThreadPage(raw);
+  if (!Result.isSuccess(decoded)) return Result.fail(decoded.failure);
+  const times: Array<string | null | undefined> = [];
+  for (const entry of decoded.success.value) {
+    const decodedThread = decodeThreadEntry(entry);
+    if (Exit.isFailure(decodedThread)) continue;
+    const thread = decodedThread.value;
+    times.push(thread.publishedDate, thread.lastUpdatedDate);
+    for (const comment of thread.comments ?? []) {
+      times.push(comment.publishedDate, comment.lastUpdatedDate);
+    }
+  }
+  return Result.succeed(latestAzureDevOpsTime(times));
+}
+
 const RawIterationSchema = Schema.Struct({
   id: Schema.Int,
   sourceRefCommit: Schema.optional(