removed support for implicit local modules

`require.resolve` behavior was changed in Node v12 to comply with Node
resolution algorithm (see nodejs/node#29139) -
not sure why we thought this behavior was desirable in the first place
(introduced in 3142f2e - probably
cargo-culting `require.resolve`'s observed behavior)

however, on legacy Node versions behavior appears unchanged if the
current working directory is the same as `rootDir` - I didn't bother
enforcing modern behavior because legacy isn't worth the effort

in the process, fixed legacy detection

.travis.yml

@@ -1,5 +1,6 @@
 language: node_js
 node_js:
+- 8.9.3
 - 8
 - 10
 

lib/util/resolve.js

@@ -9,7 +9,7 @@ if(!legacy) { // account for bug in Node v8.9.4 and below
 	let { version } = process;
 	if(version.substr(0, 3) === "v8.") {
 		let [minor, patch] = version.substr(3).split(".").map(i => parseInt(i, 10));
-		legacy = minor < 8 || patch <= 4;
+		legacy = minor <= 9 && patch <= 4;
 	}
 }
 
@@ -31,7 +31,7 @@ function resolveModulePath(filepath, rootDir) {
 	if(legacy) {
 		legacy = process.env.NODE_PATH; // cache previous value
 		rootDir = rootDir.replace(/\/{1,}$/, ""); // strip trailing slashes, to be safe
-		process.env.NODE_PATH = `${rootDir}:${rootDir}/node_modules`;
+		process.env.NODE_PATH = `${rootDir}/node_modules`;
 		require("module").Module._initPaths();
 	}
 

test/test_manager.js

@@ -7,32 +7,45 @@ let assert = require("assert");
 
 let assertSame = assert.strictEqual;
 
+let [major] = process.version.substr(1).split(".").map(i => parseInt(i, 10));
+let MODERN = major >= 12; // legacy doesn't throw due to working directory
+
 describe("asset manager", _ => {
 	let root = path.resolve(__dirname, "fixtures");
 	let cwd;
+	let { exit } = process;
 
 	before(() => {
 		cwd = process.cwd();
 		process.chdir(root);
+		process.exit = code => {
+			throw new Error(`exit ${code}`);
+		};
 	});
 
 	after(() => {
 		process.chdir(cwd);
+		process.exit = exit;
 	});
 
-	it("resolves file paths for local modules and third-party packages", () => {
+	it("resolves file paths for third-party packages", () => {
 		let { resolvePath } = new AssetManager(root);
 
-		let filepath = resolvePath("dummy/src.js");
+		let filepath = resolvePath("dummy/pkg.js");
+		assertSame(path.relative(root, filepath), "node_modules/dummy/pkg.js");
+
+		filepath = resolvePath("./dummy/src.js");
 		assertSame(path.relative(root, filepath), "dummy/src.js");
 
-		filepath = resolvePath("dummy/pkg.js");
-		assertSame(path.relative(root, filepath), "node_modules/dummy/pkg.js");
+		if(MODERN) {
+			assert.throws(() => {
+				resolvePath("dummy/src.js");
+			}, /exit 1/);
 
-		// local modules take precedence over third-party packages
-		["dummy", "dummy/index", "dummy/index.js"].forEach(module => {
-			let filepath = resolvePath(module);
-			assertSame(path.relative(root, filepath), "dummy/index.js");
-		});
+			["dummy", "dummy/index", "dummy/index.js"].forEach(module => {
+				let filepath = resolvePath(module);
+				assertSame(path.relative(root, filepath), "node_modules/dummy/index.js");
+			});
+		}
 	});
 });