test: re-implement original tests

example/basic/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "baseUrl": "hej"
+  }
+}

example/extend-multiple/dir1/dir2/tsconfig.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "foo": [
+        "bar2"
+      ]
+    }
+  }
+}

example/extend-multiple/dir1/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "baseUrl": "."
+  }
+}

example/extend-multiple/tsconfig.base.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "foo": [
+        "bar"
+      ]
+    }
+  }
+}

example/extend-multiple/tsconfig.json

@@ -0,0 +1,7 @@
+{
+  "extends": [
+    "./tsconfig.base.json",
+    "./dir1/tsconfig.json",
+    "./dir1/dir2/tsconfig.json"
+  ]
+}

example/extend-node-module/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "shared-tsconfig",
+  "compilerOptions": {
+    "baseUrl": "kalle",
+    "paths": {
+      "foo": [
+        "bar2"
+      ]
+    }
+  }
+}

example/extend-overwrite/nested/tsconfig.json

@@ -0,0 +1,11 @@
+{
+  "extends": "../tsconfig.base.json",
+  "compilerOptions": {
+    "baseUrl": "kalle",
+    "paths": {
+      "foo": [
+        "bar2"
+      ]
+    }
+  }
+}

example/extend-overwrite/tsconfig.base.json

@@ -0,0 +1,11 @@
+{
+  "compilerOptions": {
+    "baseUrl": "olle",
+    "paths": {
+      "foo": [
+        "bar1"
+      ]
+    },
+    "strict": true
+  }
+}

example/extend-without-extension/tsconfig.base.json

@@ -0,0 +1,10 @@
+{
+  "compilerOptions": {
+    "baseUrl": ".",
+    "paths": {
+      "foo": [
+        "bar"
+      ]
+    }
+  }
+}

example/extend-without-extension/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "extends": [
+    "./tsconfig.base"
+  ]
+}

example/invalid/tsconfig.json

@@ -0,0 +1,8 @@
+{
+  "compilerOptions": {
+    "paths": {
+      "foo": [
+        "bar"
+      ]
+    }
+  }

example/resolve-closest/dir1/dir2/tsconfig.json

@@ -0,0 +1,3 @@
+{
+  "extends": "../tsconfig.json"
+}

example/resolve-closest/dir1/tsconfig.json

@@ -0,0 +1,3 @@
+{
+  "extends": "../tsconfig.json"
+}

example/resolve-closest/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": {
+    "baseUrl": "."
+  }
+}

example/with-comments/tsconfig.json

@@ -0,0 +1,6 @@
+{
+  // my comment
+  "compilerOptions": { 
+    "baseUrl": "hej"
+  }
+}

example/with-trailing-commas/tsconfig.json

@@ -0,0 +1,5 @@
+{
+  "compilerOptions": { 
+    "baseUrl": "hej",
+  },
+}

src/__tests__/tsconfig-loader.test.ts

@@ -164,13 +164,124 @@ describe("walkForTsConfig", () => {
 });
 
 describe("loadSyncDefault", () => {
-  it("should result multiple levels of tsconfig extension", () => {
-    const cwd = resolve(__dirname, "../../example/inherited");
+  it("should load a config", () => {
+    const cwd = resolve(__dirname, "../../example/basic")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./hej",
+      paths: {},
+      tsConfigPath: resolve(cwd, "tsconfig.json"),
+    });
+  });
+
+  it("should load a config with comments", () => {
+    const cwd = resolve(__dirname, "../../example/with-comments")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./hej",
+      paths: {},
+      tsConfigPath: resolve(cwd, "tsconfig.json"),
+    });
+  });
+
+  it("should load a config with trailing commas", () => {
+    const cwd = resolve(__dirname, "../../example/with-trailing-commas")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./hej",
+      paths: {},
+      tsConfigPath: resolve(cwd, "tsconfig.json"),
+    });
+  });
+
+  it("should gracefully handle invalid JSON5", () => {
+    const cwd = resolve(__dirname, "../../example/invalid")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: undefined,
+      paths: { foo: ['bar'] },
+      tsConfigPath: resolve(cwd, 'tsconfig.json')
+    });
+  });
+
+  it("should load a config with string extends and overwrite all options", () => {
+    const cwd = resolve(__dirname, "../../example/extend-overwrite")
+    const tsConfigPath = resolve(cwd, 'nested/tsconfig.json');
+
     const result = tsConfigLoader({
       cwd,
-      getEnv: (_: string) => undefined,
+      getEnv: (name: string) => name === 'TS_NODE_PROJECT' ? tsConfigPath : undefined
     });
 
+    expect(result).toEqual({
+      baseUrl: "./kalle",
+      paths: { foo: ["bar2"] },
+      strict: true,
+      tsConfigPath
+    });
+  });
+
+  it("should load a config with string extends from node_modules and overwrite all options", () => {
+    const cwd = resolve(__dirname, "../../example/extend-node-module")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./kalle",
+      paths: { foo: ["bar2"] },
+      strict: true,
+      tsConfigPath: resolve(cwd, "tsconfig.json")
+    });
+  });
+
+  it("should use baseUrl relative to location of extended tsconfig", () => {
+    const cwd = resolve(__dirname, "../../example/resolve-closest/dir1/dir2")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "../..",
+      paths: {},
+      tsConfigPath: resolve(cwd, "tsconfig.json")
+    });
+  });
+
+  it("should load a config with array extends and overwrite all options", () => {
+    const cwd = resolve(__dirname, "../../example/extend-multiple")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./dir1/dir2",
+      paths: { foo: ["bar2"] },
+      tsConfigPath: resolve(cwd, "tsconfig.json")
+    });
+  });
+
+  it("should load a config with array extends without .json extension", () => {
+    const cwd = resolve(__dirname, "../../example/extend-without-extension")
+
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
+    expect(result).toEqual({
+      baseUrl: "./",
+      paths: { foo: ["bar"] },
+      tsConfigPath: resolve(cwd, "tsconfig.json")
+    });
+  });
+
+  it("should resolve multiple levels of tsconfig extension", () => {
+    const cwd = resolve(__dirname, "../../example/inherited");
+    const result = tsConfigLoader({ cwd, getEnv: () => undefined });
+
     expect(result).toEqual({
       baseUrl: undefined,
       paths: { "@": [] },

src/tsconfig-loader.ts

@@ -64,17 +64,9 @@ function loadSyncDefault(
 
   return {
     tsConfigPath: configPath,
-    baseUrl:
-      baseUrl ||
-      (tsconfig &&
-        tsconfig.config.compilerOptions &&
-        tsconfig.config.compilerOptions.baseUrl) ||
-      undefined,
-    paths:
-      (tsconfig &&
-        tsconfig.config.compilerOptions &&
-        tsconfig.config.compilerOptions.paths) ??
-      {},
+    ...tsconfig?.config.compilerOptions,
+    baseUrl: baseUrl || tsconfig?.config.compilerOptions?.baseUrl,
+    paths: tsconfig?.config.compilerOptions?.paths ?? {},
   };
 }