Fix missing paths when using typescript's module nodenext feature (#216)

* Fix missing paths when using typescript's module nodenext feature

This resolution requires relative/mapped import paths to end with .js

Reference https://devblogs.microsoft.com/typescript/announcing-typescript-4-5-beta/#esm-nodejs

* Add tests from #213

#213

* Add support for .mjs, .cjs and .jsx files

src/__tests__/data/match-path-data.ts

@@ -227,4 +227,15 @@ export const tests: ReadonlyArray<OneTest> = [
     expectedPath: join("/root", "mylib", "index.cjs"),
     extensions: defaultExtensionsWhenRunningInTsNode,
   },
+  {
+    name: "should resolve .ts from .js alias",
+    absoluteBaseUrl: "/root/",
+    paths: {
+      "@/*": ["src/*"],
+    },
+    existingFiles: [join("/root", "src", "foo.ts")],
+    requestedModule: "@/foo.js",
+    expectedPath: join("/root", "src", "foo"),
+    extensions: defaultExtensionsWhenRunningInTsNode,
+  },
 ];

src/__tests__/try-path.test.ts

@@ -95,6 +95,79 @@ describe("mapping-entry", () => {
     ]);
   });
 
+  it.each(["js", "jsx", "mjs", "cjs"])(
+    "should include paths with ending .%s removed that matches requested module",
+    (extension) => {
+      const result = getPathsToTry(
+        [".ts", ".tsx"],
+        [
+          {
+            pattern: "longest/pre/fix/*",
+            paths: [join("/absolute", "base", "url", "foo2", "*")],
+          },
+        ],
+        `longest/pre/fix/bar.${extension}`
+      );
+
+      expect(result).toEqual(
+        expect.arrayContaining([
+          {
+            type: "extension",
+            path: join("/absolute", "base", "url", "foo2", "bar.ts"),
+          },
+          {
+            type: "extension",
+            path: join("/absolute", "base", "url", "foo2", "bar.tsx"),
+          },
+        ])
+      );
+    }
+  );
+
+  it.each([
+    ["mjs", "mts"],
+    ["cjs", "cts"],
+  ])(
+    "should include paths with ending .%s removed that matches requested module with extension .%s",
+    (requestedModuleExtension, expectedExtension) => {
+      const result = getPathsToTry(
+        [".ts", ".tsx", `.${expectedExtension}`, `.${expectedExtension}x`],
+        [
+          {
+            pattern: "longest/pre/fix/*",
+            paths: [join("/absolute", "base", "url", "foo2", "*")],
+          },
+        ],
+        `longest/pre/fix/bar.${requestedModuleExtension}`
+      );
+
+      expect(result).toEqual(
+        expect.arrayContaining([
+          {
+            type: "extension",
+            path: join(
+              "/absolute",
+              "base",
+              "url",
+              "foo2",
+              `bar.${expectedExtension}`
+            ),
+          },
+          {
+            type: "extension",
+            path: join(
+              "/absolute",
+              "base",
+              "url",
+              "foo2",
+              `bar.${expectedExtension}x`
+            ),
+          },
+        ])
+      );
+    }
+  );
+
   it("should resolve paths starting with a slash", () => {
     const result = getPathsToTry(
       [".ts"],

src/try-path.ts

@@ -24,6 +24,7 @@ export function getPathsToTry(
     return undefined;
   }
 
+  const suffixRegex = /\.(c|m)?jsx?$/;
   const pathsToTry: Array<TryPath> = [];
   for (const entry of absolutePathMappings) {
     const starMatch =
@@ -39,6 +40,17 @@ export function getPathsToTry(
             (e) => ({ type: "extension", path: physicalPath + e } as TryPath)
           )
         );
+        if (physicalPath.match(suffixRegex)) {
+          pathsToTry.push(
+            ...extensions.map(
+              (e) =>
+                ({
+                  type: "extension",
+                  path: physicalPath.replace(suffixRegex, "") + e,
+                } as TryPath)
+            )
+          );
+        }
         pathsToTry.push({
           type: "package",
           path: path.join(physicalPath, "/package.json"),