fix: Use package.json location as project root

src/__tests__/config.test.ts

@@ -0,0 +1,50 @@
+import { chdir, cwd } from "node:process";
+
+import tmp from "tmp";
+
+import { Config } from "../config";
+import { basename, join } from "node:path";
+import { mkdirSync, writeFileSync } from "node:fs";
+import { PackageJson } from "type-fest";
+
+tmp.setGracefulCleanup();
+
+describe(Config, () => {
+  it("respects environment variables", () => {
+    process.env.APPMAP_ROOT = "/test/app";
+    expect(new Config()).toMatchObject({
+      root: "/test/app",
+      appmapDir: "/test/app/tmp/appmap",
+      appName: "app",
+    });
+  });
+
+  it("uses the current directory for root", () => {
+    expect(new Config()).toMatchObject({
+      root: dir,
+      appmapDir: join(dir, "tmp", "appmap"),
+      appName: basename(dir),
+    });
+  });
+
+  it("searches for package.json and uses package name from it", () => {
+    writeFileSync("package.json", JSON.stringify({ name: "test-package" } as PackageJson));
+
+    mkdirSync("subdirectory");
+    chdir("subdirectory");
+    expect(new Config()).toMatchObject({
+      root: dir,
+      appmapDir: join(dir, "tmp", "appmap"),
+      appName: "test-package",
+    });
+  });
+});
+
+let dir: string;
+beforeEach(() => {
+  chdir((dir = tmp.dirSync().name));
+  jest.replaceProperty(process, "env", {});
+});
+
+const origCwd = cwd();
+afterEach(() => chdir(origCwd));

src/config.ts

@@ -1,16 +1,23 @@
-import { dirname, join } from "node:path";
+import { basename, join } from "node:path";
 import { cwd } from "node:process";
 
-import { readPkgUp } from "./util/readPkgUp";
+import locateFileUp from "./util/findFileUp";
+import { readFileSync } from "node:fs";
+import { PackageJson } from "type-fest";
 
 export class Config {
   public readonly appmapDir: string;
   public readonly appName: string;
+  public readonly root: string;
 
-  constructor(public readonly root = process.env.APPMAP_ROOT ?? cwd()) {
+  constructor() {
+    const packageDir = locateFileUp("package.json", process.env.APPMAP_ROOT ?? cwd());
+    const root = (this.root = process.env.APPMAP_ROOT ?? packageDir ?? cwd());
     this.appmapDir = join(root, "tmp", "appmap");
-    const targetPackage = readPkgUp(root);
-    this.appName = targetPackage?.name ?? dirname(root);
+    const targetPackage = packageDir
+      ? (JSON.parse(readFileSync(join(packageDir, "package.json"), "utf8")) as PackageJson)
+      : undefined;
+    this.appName = targetPackage?.name ?? basename(root);
   }
 
   export() {

src/util/findFileUp.ts

@@ -0,0 +1,10 @@
+import { existsSync } from "node:fs";
+import { dirname, join } from "node:path";
+import { cwd } from "node:process";
+
+export default function locateFileUp(filename: string, dir = cwd()): string | undefined {
+  if (existsSync(join(dir, filename))) return dir;
+  const parent = dirname(dir);
+  if (parent === dir) return;
+  return locateFileUp(filename, parent);
+}

src/util/readPkgUp.ts

@@ -1,13 +1,10 @@
 import { readFileSync } from "node:fs";
-import { dirname, join } from "node:path";
+import { join } from "node:path";
+
 import type { PackageJson } from "type-fest";
+import findFileUp from "./findFileUp";
 
 export function readPkgUp(dir: string): PackageJson | undefined {
-  try {
-    return JSON.parse(readFileSync(join(dir, "package.json"), "utf-8")) as PackageJson;
-  } catch {
-    const parent = dirname(dir);
-    if (parent === dir) return;
-    else return readPkgUp(parent);
-  }
+  const path = findFileUp("package.json", dir);
+  if (path) return JSON.parse(readFileSync(join(path, "package.json"), "utf-8")) as PackageJson;
 }