Alias paths on integration tests (#3196)

* Run pretest in CI to build all tests

* Alias paths when running tests

.vscode-test.mjs

@@ -6,6 +6,10 @@ export default defineConfig({
 	mocha: {
 		ui: "bdd",
 		timeout: 20000, // Maximum time (in ms) that a test can run before failing
+		/** Set up alias path resolution during tests
+		 * @See {@link file://./test-setup.js}
+		 */
+		require: ["./test-setup.js"],
 	},
 	workspaceFolder: "test-workspace",
 	version: "stable",

test-setup.js

@@ -0,0 +1,22 @@
+const tsConfigPaths = require("tsconfig-paths")
+const fs = require("fs")
+
+const tsConfig = JSON.parse(fs.readFileSync("./tsconfig.json", "utf-8"))
+
+/**
+ * The aliases point towards the `src` directory.
+ * However, `tsc` doesn't compile paths by itself
+ * (https://www.typescriptlang.org/docs/handbook/modules/reference.html#paths-does-not-affect-emit)
+ * So we need to use tsconfig-paths to resolve the aliases when running tests,
+ * but pointing to `out` instead.
+ */
+const outPaths = {}
+Object.keys(tsConfig.compilerOptions.paths).forEach((key) => {
+	const value = tsConfig.compilerOptions.paths[key]
+	outPaths[key] = value.map((path) => path.replace("src", "out"))
+})
+
+tsConfigPaths.register({
+	baseUrl: ".",
+	paths: outPaths,
+})