fix(coding-agent): fix changelog links

Fixes #5516

packages/coding-agent/src/utils/changelog.ts

@@ -1,3 +1,4 @@
+import path from "node:path";
 import { existsSync, readFileSync } from "fs";
 
 export interface ChangelogEntry {
@@ -7,6 +8,102 @@ export interface ChangelogEntry {
 	content: string;
 }
 
+const GITHUB_REPO = "earendil-works/pi";
+const CHANGELOG_LINK_BASE_PATH = "packages/coding-agent";
+const LEGACY_REPO_RE = /^https:\/\/github\.com\/(?:badlogic|earendil-works)\/pi-mono(?=\/|$)/;
+const URL_SCHEME_RE = /^[a-z][a-z0-9+.-]*:/i;
+const INLINE_MARKDOWN_LINK_RE = /(!?\[[^\]\n]+\]\()([^\s)]+)((?:\s+[^)]*)?\))/g;
+
+function entryVersion(entry: ChangelogEntry): string {
+	return `${entry.major}.${entry.minor}.${entry.patch}`;
+}
+
+function normalizeTag(version: string | ChangelogEntry): string {
+	const versionString = typeof version === "string" ? version : entryVersion(version);
+	return versionString.startsWith("v") ? versionString : `v${versionString}`;
+}
+
+function splitLocalTarget(target: string): { fragment: string; pathPart: string; query: string } {
+	const hashIndex = target.indexOf("#");
+	const beforeHash = hashIndex === -1 ? target : target.slice(0, hashIndex);
+	const fragment = hashIndex === -1 ? "" : target.slice(hashIndex);
+	const queryIndex = beforeHash.indexOf("?");
+
+	if (queryIndex === -1) {
+		return { fragment, pathPart: beforeHash, query: "" };
+	}
+
+	return {
+		fragment,
+		pathPart: beforeHash.slice(0, queryIndex),
+		query: beforeHash.slice(queryIndex),
+	};
+}
+
+function normalizePathPart(value: string): string {
+	return value.replaceAll("\\", "/");
+}
+
+function resolveRepositoryPath(targetPath: string): string | undefined {
+	const normalizedTarget = normalizePathPart(targetPath);
+	const joined = normalizedTarget.startsWith("/")
+		? path.posix.normalize(normalizedTarget.replace(/^\/+/, ""))
+		: path.posix.normalize(path.posix.join(CHANGELOG_LINK_BASE_PATH, normalizedTarget));
+
+	if (joined === "." || joined.startsWith("../") || joined === "..") {
+		return undefined;
+	}
+
+	return joined;
+}
+
+function isDirectoryTarget(originalPath: string, repositoryPath: string): boolean {
+	if (originalPath.endsWith("/")) {
+		return true;
+	}
+
+	const basename = path.posix.basename(repositoryPath);
+	return !basename.includes(".");
+}
+
+function normalizeChangelogLinkTarget(target: string, tag: string): string {
+	let canonicalTarget = target.replace(LEGACY_REPO_RE, `https://github.com/${GITHUB_REPO}`);
+	const repoUrl = `https://github.com/${GITHUB_REPO}`;
+
+	for (const route of ["blob", "tree"]) {
+		for (const branch of ["main", "master"]) {
+			const floatingRefPrefix = `${repoUrl}/${route}/${branch}/`;
+			if (canonicalTarget.startsWith(floatingRefPrefix)) {
+				canonicalTarget = `${repoUrl}/${route}/${tag}/${canonicalTarget.slice(floatingRefPrefix.length)}`;
+			}
+		}
+	}
+
+	if (canonicalTarget.startsWith("#") || canonicalTarget.startsWith("//") || URL_SCHEME_RE.test(canonicalTarget)) {
+		return canonicalTarget;
+	}
+
+	const { fragment, pathPart, query } = splitLocalTarget(canonicalTarget);
+	if (!pathPart) {
+		return canonicalTarget;
+	}
+
+	const repositoryPath = resolveRepositoryPath(pathPart);
+	if (!repositoryPath) {
+		return canonicalTarget;
+	}
+
+	const route = isDirectoryTarget(pathPart, repositoryPath) ? "tree" : "blob";
+	return `https://github.com/${GITHUB_REPO}/${route}/${tag}/${encodeURI(repositoryPath)}${query}${fragment}`;
+}
+
+export function normalizeChangelogLinks(markdown: string, version: string | ChangelogEntry): string {
+	const tag = normalizeTag(version);
+	return markdown.replace(INLINE_MARKDOWN_LINK_RE, (_match, prefix, target, suffix) => {
+		return `${prefix}${normalizeChangelogLinkTarget(target, tag)}${suffix}`;
+	});
+}
+
 /**
  * Parse changelog entries from CHANGELOG.md
  * Scans for ## lines and collects content until next ## or EOF