packages/cli: make src-relative imports work

packages/cli/bin/backstage-cli

@@ -5,12 +5,60 @@ const path = require('path');
 // Figure out whether we're running inside the backstage repo or as an installed dependency
 const isLocal = require('fs').existsSync(path.resolve(__dirname, '../src'));
 if (!isLocal) {
+  // src-relative imports are a pain to get to work with plain tsc compilation, as the
+  // transpiled code will maintain the imports as they are in the source. Which means an
+  // import for `helpers/paths` will start like that in the output, which won't work in NodeJS.
+  //
+  // This is a solution for getting src-relative imports to work with typescript/node in
+  // the published package. We're using `module: "amd"` to ship the entire cli implementation
+  // in one file, and it also happens to generate correct module definition and import statements.
+
+  // Minimal AMD implementation
+  const moduleFactories = {};
+  const moduleCache = {};
+  global.define = (name, deps, moduleFunc) => {
+    moduleFactories[name] = () => {
+      const exportsObj = {};
+      const impls = deps.slice(2).map(dep => {
+        const factory = moduleFactories[dep];
+        if (!factory) {
+          return require(dep);
+        }
+        if (!moduleCache[dep]) {
+          moduleCache[dep] = factory();
+        }
+        return moduleCache[dep];
+      });
+
+      moduleFunc(require, exportsObj, ...impls);
+
+      return exportsObj;
+    };
+  };
   require('../dist');
+
+  // index module is the entrypoint
+  moduleFactories.index();
 } else {
+  const tsConfigPath = path.resolve(__dirname, '../tsconfig.json');
+  const {
+    baseUrl: relativeBaseUrl,
+    paths = {},
+  } = require(tsConfigPath).compilerOptions;
+  const baseUrl = path.resolve(__dirname, '..', relativeBaseUrl);
+
+  // Use tsconfig-paths to resolve src-relative paths during development
+  const cleanupPaths = require('tsconfig-paths').register({ baseUrl, paths });
+
   require('ts-node').register({
     project: path.resolve(__dirname, '../tsconfig.json'),
+    compilerOptions: {
+      module: 'CommonJS',
+    },
     transpileOnly: true,
   });
 
   require('../src');
+
+  cleanupPaths();
 }

packages/cli/config/jest.js

@@ -24,7 +24,9 @@ if (fs.existsSync('jest.config.js')) {
 } else if (fs.existsSync('jest.config.ts')) {
   module.exports = require(path.resolve('jest.config.ts'));
 } else {
-  const extraOptions = {};
+  const extraOptions = {
+    modulePaths: ['<rootDir>'],
+  };
 
   // Use src/setupTests.ts as the default location for configuring test env
   if (fs.existsSync('src/setupTests.ts')) {

packages/cli/package.json

@@ -39,7 +39,8 @@
     "@types/webpack-dev-server": "^3.10.0",
     "del": "^5.1.0",
     "nodemon": "^2.0.2",
-    "ts-node": "^8.6.2"
+    "ts-node": "^8.6.2",
+    "tsconfig-paths": "^3.9.0"
   },
   "bin": {
     "backstage-cli": "bin/backstage-cli"

packages/cli/src/helpers/paths.ts

@@ -77,8 +77,22 @@ export function findRootPath(topPath: string): string {
   );
 }
 
+// Finds the root of the cli package itself
+export function findOwnDir() {
+  // Known relative locations of package in dist/dev
+  const pathDist = '..';
+  const pathDev = '../..';
+
+  // Check the closest dir first
+  const pkgInDist = resolvePath(__dirname, pathDist, 'package.json');
+  const isDist = fs.pathExistsSync(pkgInDist);
+
+  const path = isDist ? pathDist : pathDev;
+  return resolvePath(__dirname, path);
+}
+
 export function findPaths(): Paths {
-  const ownDir = resolvePath(__dirname, '../..');
+  const ownDir = findOwnDir();
   const targetDir = fs.realpathSync(process.cwd());
 
   // We're not always running in a monorepo, so we lazy init this to only crash commands

packages/cli/tsconfig.json

@@ -2,11 +2,8 @@
   "extends": "../../tsconfig.json",
   "include": ["src"],
   "compilerOptions": {
-    "outDir": "dist",
-    "module": "CommonJS",
-    "baseUrl": "src",
-    "paths": {
-      "*": ["src/*"]
-    }
+    "outFile": "dist/index.js",
+    "module": "amd",
+    "baseUrl": "src"
   }
 }