Initial Commit

lib/context.ts

@@ -0,0 +1,50 @@
+import { AsyncLocalStorage } from "node:async_hooks";
+import type { ComposeSpecification } from "../schema/docker.d";
+import { getProject, throwWhen } from "./shared";
+import { readCompose, resolveComposeFile } from "./yaml";
+
+type AppContext = {
+  project: string;
+  cwd: string;
+  path(): Promise<string | undefined>;
+  compose(): Promise<ComposeSpecification>;
+};
+
+const appContext = new AsyncLocalStorage<AppContext>();
+
+export function provideContext<T>(fn: () => T): T {
+  const cwd = process.cwd();
+  const path = createCachedGetter("composeFile", () => resolveComposeFile(cwd));
+  return appContext.run(
+    {
+      project: getProject(),
+      cwd,
+      path,
+      compose: createCachedGetter("compose", () =>
+        path()
+          .then(throwWhen((path): path is undefined => path === undefined))
+          .then(readCompose),
+      ),
+    },
+    fn,
+  );
+}
+
+export function ctx() {
+  const store = appContext.getStore();
+  if (!store) throw new Error("Not in context!");
+  return store;
+}
+
+const cache: Record<string, unknown> = {};
+export function createCachedGetter<T>(
+  key: string,
+  fn: () => Promise<T>,
+): () => Promise<T> {
+  return async () => {
+    if (key in cache) return cache[key] as T;
+    const result = await fn();
+    cache[key] = result;
+    return result;
+  };
+}