From a25b92542d8984f4df5f0b7052c470dbccb437a1 Mon Sep 17 00:00:00 2001
From: Hiroki Osame <hiroki.osame@gmail.com>
Date: Fri, 15 Sep 2023 00:18:19 +0900
Subject: [PATCH] fix(tsconfig paths): support paths starting with slash (#75)

---
 src/loaders.ts                                             | 4 ++--
 .../package-module/tsconfig/src/paths-slash-match.ts       | 3 +++
 tests/fixtures/package-module/tsconfig/tsconfig.json       | 3 ++-
 tests/index.ts                                             | 7 +++++--
 tests/specs/typescript/tsconfig.ts                         | 7 +++++++
 5 files changed, 19 insertions(+), 5 deletions(-)
 create mode 100644 tests/fixtures/package-module/tsconfig/src/paths-slash-match.ts

diff --git a/src/loaders.ts b/src/loaders.ts
index c68494f..ad41edf 100644
--- a/src/loaders.ts
+++ b/src/loaders.ts
@@ -125,7 +125,7 @@ async function tryDirectory(
 	}
 }
 
-const isPathPattern = /^\.{0,2}\//;
+const isRelativePathPattern = /^\.{1,2}\//;
 
 const supportsNodePrefix = (
 	compareNodeVersion([14, 13, 1]) >= 0
@@ -151,7 +151,7 @@ export const resolve: resolve = async function (
 
 	const isPath = (
 		specifier.startsWith(fileProtocol)
-		|| isPathPattern.test(specifier)
+		|| isRelativePathPattern.test(specifier)
 	);
 
 	if (
diff --git a/tests/fixtures/package-module/tsconfig/src/paths-slash-match.ts b/tests/fixtures/package-module/tsconfig/src/paths-slash-match.ts
new file mode 100644
index 0000000..c906c5a
--- /dev/null
+++ b/tests/fixtures/package-module/tsconfig/src/paths-slash-match.ts
@@ -0,0 +1,3 @@
+import value from '/nested-resolve-target';
+
+console.log(value);
diff --git a/tests/fixtures/package-module/tsconfig/tsconfig.json b/tests/fixtures/package-module/tsconfig/tsconfig.json
index 9d0c412..ea35d97 100644
--- a/tests/fixtures/package-module/tsconfig/tsconfig.json
+++ b/tests/fixtures/package-module/tsconfig/tsconfig.json
@@ -7,7 +7,8 @@
 		"paths": {
 			"paths-exact-match": ["resolve-target"],
 			"p/*": ["utils/*"],
-			"*/s": ["utils/*"]
+			"*/s": ["utils/*"],
+			"/*": ["utils/*"]
 		},
 	},
 }
diff --git a/tests/index.ts b/tests/index.ts
index 62a19cb..1711bcf 100644
--- a/tests/index.ts
+++ b/tests/index.ts
@@ -2,16 +2,19 @@ import { describe } from 'manten';
 import { createNode } from './utils/node-with-loader.js';
 
 const nodeVersions = [
-	'18',
 	'20',
 	...(
-		process.env.CI
+		(
+			process.env.CI
+			&& process.platform !== 'win32'
+		)
 			? [
 				'12.20.0', // CJS named export detection added
 				'12',
 				'14',
 				'16',
 				'17',
+				'18',
 			]
 			: []
 	),
diff --git a/tests/specs/typescript/tsconfig.ts b/tests/specs/typescript/tsconfig.ts
index 2ae6e9c..23afa76 100644
--- a/tests/specs/typescript/tsconfig.ts
+++ b/tests/specs/typescript/tsconfig.ts
@@ -113,6 +113,13 @@ export default testSuite(async ({ describe }, node: NodeApis) => {
 				expect(nodeProcess.stdout).toBe('nested-resolve-target');
 			});
 
+			test('resolves paths slash prefix', async () => {
+				const nodeProcess = await node.load('./src/paths-slash-match.ts', {
+					cwd: './tsconfig',
+				});
+				expect(nodeProcess.stdout).toBe('nested-resolve-target');
+			});
+
 			test('resolves paths suffix', async () => {
 				const nodeProcess = await node.load('./src/paths-suffix-match.ts', {
 					cwd: './tsconfig',