BBC2-14 add bb pr diff

src/backend/pullrequests/index.test.ts

@@ -7,6 +7,7 @@ import {
 	createPullRequestComment,
 	findOpenPullRequestForBranch,
 	getPullRequest,
+	getPullRequestDiff,
 	listEffectiveDefaultReviewers,
 	listPullRequests,
 	type PullRequest,
@@ -919,3 +920,42 @@ describe("review action endpoints (approve / unapprove / request-changes / unreq
 		expect((err as PullRequestError).status).toBe(404);
 	});
 });
+
+describe("getPullRequestDiff", () => {
+	const DIFF_PATH = (id: number) =>
+		`${BITBUCKET_BASE}/repositories/ws/repo/pullrequests/${id}/diff`;
+
+	test("returns the raw text/plain body the server sent back", async () => {
+		const diffText =
+			"diff --git a/foo.ts b/foo.ts\n--- a/foo.ts\n+++ b/foo.ts\n@@ -1 +1 @@\n-old\n+new\n";
+		server.use(
+			http.get(DIFF_PATH(42), () =>
+				HttpResponse.text(diffText, {
+					headers: { "content-type": "text/plain" },
+				}),
+			),
+		);
+
+		const out = await getPullRequestDiff(creds, ref, 42);
+		expect(out).toBe(diffText);
+	});
+
+	test("empty PR diffs come back as empty string", async () => {
+		server.use(http.get(DIFF_PATH(42), () => HttpResponse.text("")));
+
+		const out = await getPullRequestDiff(creds, ref, 42);
+		expect(out).toBe("");
+	});
+
+	test("throws PullRequestError on 404", async () => {
+		server.use(
+			http.get(DIFF_PATH(99), () =>
+				HttpResponse.text("not found", { status: 404 }),
+			),
+		);
+
+		const err = await getPullRequestDiff(creds, ref, 99).catch((e) => e);
+		expect(err).toBeInstanceOf(PullRequestError);
+		expect((err as PullRequestError).status).toBe(404);
+	});
+});

src/backend/pullrequests/index.ts

@@ -1,5 +1,7 @@
 import type { components } from "../../shared/bitbucket-http/generated";
 import {
+	BASE_URL,
+	basicAuthHeader,
 	type Credentials,
 	createBitbucketClient,
 } from "../../shared/bitbucket-http/index.ts";
@@ -382,6 +384,41 @@ export async function listEffectiveDefaultReviewers(
 	return uuids;
 }
 
+/**
+ * Returns the raw unified-diff text for a PR. Bypasses the typed openapi-fetch
+ * client because `GET /pullrequests/{id}/diff` returns a 302 redirect to
+ * `/repositories/{ws}/{slug}/diff/{spec}` which serves `text/plain`, not JSON
+ * (see docs/bb-notes.md → PR diff). Content is returned as a string — the
+ * API's actual encoding is "whatever the files use" and we pass it through
+ * verbatim.
+ */
+export async function getPullRequestDiff(
+	credentials: Credentials,
+	ref: { workspace: string; slug: string },
+	pullRequestId: number,
+): Promise<string> {
+	const url = `${BASE_URL}/repositories/${encodeURIComponent(ref.workspace)}/${encodeURIComponent(ref.slug)}/pullrequests/${pullRequestId}/diff`;
+	const response = await fetch(url, {
+		method: "GET",
+		headers: {
+			Authorization: basicAuthHeader(credentials),
+			// Don't request application/json — the target serves text/plain.
+			Accept: "text/plain",
+		},
+		// `fetch` follows the 302 automatically.
+		redirect: "follow",
+	});
+
+	if (!response.ok) {
+		throw new PullRequestError(
+			`Failed to fetch diff for pull request #${pullRequestId}: HTTP ${response.status}.`,
+			response.status,
+		);
+	}
+
+	return await response.text();
+}
+
 export type PullRequestCommentResult = {
 	id: number;
 	url: string;

src/commands/pullrequest/diff.ts

@@ -0,0 +1,53 @@
+import {
+	getPullRequestDiff,
+	PullRequestError,
+} from "../../backend/pullrequests/index.ts";
+import { loadConfigOrExit } from "../../shared/config/index.ts";
+import type { Renderer } from "../../shared/renderer/index.ts";
+import {
+	RepositoryResolutionError,
+	resolveRepository,
+} from "../../shared/repository/index.ts";
+import { resolveCurrentPullRequestId } from "./current.ts";
+
+export type PullRequestDiffOptions = {
+	repository?: string;
+};
+
+export async function runPullRequestDiff(
+	renderer: Renderer,
+	idArg: string | undefined,
+	options: PullRequestDiffOptions,
+): Promise<void> {
+	const config = await loadConfigOrExit(renderer);
+
+	try {
+		const ref = await resolveRepository({ override: options.repository });
+		const id = await resolveCurrentPullRequestId(idArg, {
+			renderer,
+			config,
+			ref,
+			commandName: "diff",
+		});
+
+		const diff = await getPullRequestDiff(config, ref, id);
+
+		if (renderer.json) {
+			renderer.detail({ diff }, []);
+			return;
+		}
+		// Text mode: write the diff verbatim so pipes to `less` / `delta`
+		// work. No trailing newline added — the diff itself already ends
+		// with one when non-empty.
+		process.stdout.write(diff);
+	} catch (err) {
+		if (
+			err instanceof RepositoryResolutionError ||
+			err instanceof PullRequestError
+		) {
+			renderer.error(err.message);
+			process.exit(1);
+		}
+		throw err;
+	}
+}

src/commands/pullrequest/index.ts

@@ -2,6 +2,7 @@ import type { Command } from "commander";
 import { withRenderer } from "../../shared/renderer/commander.ts";
 import { runPullRequestComment } from "./comment.ts";
 import { runPullRequestCreate } from "./create.ts";
+import { runPullRequestDiff } from "./diff.ts";
 import { runPullRequestList } from "./list.ts";
 import { runPullRequestReview } from "./review.ts";
 import { runPullRequestView } from "./view.ts";
@@ -74,6 +75,17 @@ export function registerPullRequestCommands(program: Command): void {
 		)
 		.action(withRenderer(runPullRequestComment));
 
+	pr.command("diff")
+		.description(
+			"Print the unified diff of a pull request (defaults to the PR for the current branch)",
+		)
+		.argument("[id]", "Pull request number")
+		.option(
+			"-R, --repository <workspace/repo>",
+			"Override repository detection",
+		)
+		.action(withRenderer(runPullRequestDiff));
+
 	pr.command("review")
 		.description(
 			"Submit a review on a pull request (defaults to the PR for the current branch)",

src/shared/renderer/json.ts

@@ -19,6 +19,8 @@ export function createJsonRenderer(
 	streams: Streams = defaultStreams,
 ): Renderer {
 	return {
+		json: true,
+
 		message() {
 			// Info output is noise in a JSON pipeline — swallow it.
 		},

src/shared/renderer/text.ts

@@ -76,6 +76,8 @@ export function createTextRenderer(
 	streams: Streams = defaultStreams,
 ): Renderer {
 	return {
+		json: false,
+
 		message(text) {
 			streams.stdout(`${text}\n`);
 		},

src/shared/renderer/types.ts

@@ -20,6 +20,9 @@ export type Field<T> = {
 };
 
 export interface Renderer {
+	/** True when output is being produced in JSON mode (vs text). Lets commands
+	 * whose natural output is a raw blob (e.g. a diff) branch explicitly. */
+	readonly json: boolean;
 	/** Info output. Stdout in text mode, suppressed in JSON mode. */
 	message(text: string): void;
 	/** Errors. Always stderr, plain text regardless of mode. */