Build workspace agent, capability graph, and versioned cutovers

src/capability-language/git-resolver.ts

@@ -0,0 +1,86 @@
+import childProcess from "node:child_process";
+import crypto from "node:crypto";
+import { mkdir, readFile, realpath } from "node:fs/promises";
+import path from "node:path";
+import { promisify } from "node:util";
+import type { CapabilityRepositoryResolver } from "./assembly.js";
+
+const execFile = promisify(childProcess.execFile);
+
+const sourceKey = (kind: string, repository: string, commit: string) =>
+  `${kind}\0${repository}\0${commit.toLowerCase()}`;
+
+const checkoutName = (kind: string, repository: string, commit: string) => {
+  const digest = crypto
+    .createHash("sha256")
+    .update(sourceKey(kind, repository, commit))
+    .digest("hex")
+    .slice(0, 24);
+  return `${kind}-${digest}`;
+};
+
+export const createGitCapabilityResolver = async (options: {
+  checkoutRoot: string;
+  snapshotMap?: string;
+}): Promise<CapabilityRepositoryResolver> => {
+  await mkdir(options.checkoutRoot, { recursive: true });
+  const checkoutRoot = await realpath(options.checkoutRoot);
+  const snapshots = new Map<string, string>();
+  if (options.snapshotMap) {
+    const snapshotMapPath = await realpath(options.snapshotMap);
+    const document = JSON.parse(await readFile(snapshotMapPath, "utf8")) as {
+      resources?: Array<{
+        kind: string;
+        repository: string;
+        commit: string;
+        directory: string;
+      }>;
+    };
+    for (const entry of document.resources ?? []) {
+      if (entry.kind !== "interface" && entry.kind !== "package") {
+        throw new Error(`Snapshot map has unsupported resource kind ${entry.kind}`);
+      }
+      const key = sourceKey(entry.kind, entry.repository, entry.commit);
+      if (snapshots.has(key)) throw new Error(`Snapshot map repeats ${key}`);
+      const directory = path.resolve(path.dirname(snapshotMapPath), entry.directory);
+      snapshots.set(key, await realpath(directory));
+    }
+  }
+
+  const checkouts = new Map<string, Promise<{ directory: string }>>();
+  return async (source, kind) => {
+    const key = sourceKey(kind, source.repository, source.commit);
+    const snapshot = snapshots.get(key);
+    if (snapshot) return { directory: snapshot };
+    const existing = checkouts.get(key);
+    if (existing) return await existing;
+    const pending = (async () => {
+      const directory = path.join(
+        checkoutRoot,
+        checkoutName(kind, source.repository, source.commit),
+      );
+      await execFile("git", [
+        "-c",
+        "advice.detachedHead=false",
+        "clone",
+        "--depth",
+        "1",
+        "--single-branch",
+        "--branch",
+        `quixos-reachability/${source.commit.toLowerCase()}`,
+        source.repository,
+        directory,
+      ]);
+      const { stdout } = await execFile("git", ["-C", directory, "rev-parse", "HEAD"]);
+      if (stdout.trim().toLowerCase() !== source.commit.toLowerCase()) {
+        throw new Error(
+          `Locked commit mismatch for ${source.repository}: ` +
+          `wanted ${source.commit}, fetched ${stdout.trim()}`,
+        );
+      }
+      return { directory };
+    })();
+    checkouts.set(key, pending);
+    return await pending;
+  };
+};