fix: Relative file path imports now supports extensions

src/mapToAbsolute.js

@@ -0,0 +1,10 @@
+import path from 'path';
+
+import { toPosixPath } from './utils';
+
+export default function mapToAbsolute(currentFile, relativePath) {
+  const currentDirectory = path.dirname(currentFile);
+  const absolutePath = path.resolve(currentDirectory, relativePath);
+
+  return toPosixPath(absolutePath);
+}

src/resolvePath.js

@@ -2,8 +2,9 @@ import path from 'path';
 
 import { warn } from './log';
 import mapToRelative from './mapToRelative';
+import mapToAbsolute from './mapToAbsolute';
 import normalizeOptions from './normalizeOptions';
-import { nodeResolvePath, replaceExtension, isRelativePath, toLocalPath, toPosixPath } from './utils';
+import { nodeResolvePath, nodeResolveRelativePath, replaceExtension, isRelativePath, toLocalPath, toPosixPath } from './utils';
 
 function getRelativePath(sourcePath, currentFile, absFileInRoot, opts) {
   const realSourceFileExtension = path.extname(absFileInRoot);
@@ -77,13 +78,27 @@ function resolvePathFromAliasConfig(sourcePath, currentFile, opts) {
   return aliasedSourceFile;
 }
 
+function resolvePathFromRelativeConfig(sourcePath, currentFile, opts) {
+  if (isRelativePath(sourcePath)) {
+    const absFilePath = mapToAbsolute(currentFile, sourcePath);
+    const resolvedSourceFile = nodeResolveRelativePath(absFilePath, opts.extensions);
+
+    if (resolvedSourceFile) {
+      return getRelativePath(sourcePath, currentFile, resolvedSourceFile, opts);
+    }
+  }
+
+  return null;
+}
+
 const resolvers = [
   resolvePathFromAliasConfig,
+  resolvePathFromRelativeConfig,
   resolvePathFromRootConfig,
 ];
 
 export default function resolvePath(sourcePath, currentFile, opts) {
-  if (isRelativePath(sourcePath)) {
+  if (isRelativePath(sourcePath) && path.extname(sourcePath)) {
     return sourcePath;
   }
 

src/utils.js

@@ -9,6 +9,14 @@ export function nodeResolvePath(modulePath, basedir, extensions) {
   }
 }
 
+export function nodeResolveRelativePath(modulePath, extensions) {
+  try {
+    return resolve.sync(modulePath, { extensions });
+  } catch (e) {
+    return null;
+  }
+}
+
 export function isRelativePath(nodePath) {
   return nodePath.match(/^\.?\.\//);
 }

test/index.test.js

@@ -254,6 +254,22 @@ describe('module-resolver', () => {
         );
       });
 
+      it('should not resolve the relative file path with an unknown extension', () => {
+        testWithImport(
+          './test/testproject/src/text',
+          './test/testproject/src/text',
+          rootTransformerOpts,
+        );
+      });
+
+      it('should resolve the relative file path with a known defined extension & strip the extension', () => {
+        testWithImport(
+          './test/testproject/src/rn',
+          './test/testproject/src/rn',
+          rootTransformerOpts,
+        );
+      });
+
       it('should resolve the file path with a known defined extension & strip the extension', () => {
         testWithImport(
           'rn',
@@ -262,13 +278,22 @@ describe('module-resolver', () => {
         );
       });
 
+
       it('should resolve the file path with an explicit extension and not strip the extension', () => {
         testWithImport(
           'rn/index.ios.js',
           './test/testproject/src/rn/index.ios.js',
           rootTransformerOpts,
         );
       });
+
+      it('should resolve the relative file path with an explicit extension and not strip the extension', () => {
+        testWithImport(
+          './test/testproject/src/rn/index.ios.js',
+          './test/testproject/src/rn/index.ios.js',
+          rootTransformerOpts,
+        );
+      });
     });
 
     describe('non-standard double extensions with strip extensions', () => {
@@ -291,13 +316,30 @@ describe('module-resolver', () => {
         );
       });
 
+      it('should not resolve the relative file path with an unknown extension', () => {
+        testWithImport(
+          './test/testproject/src/text',
+          './test/testproject/src/text',
+          rootTransformerOpts,
+        );
+      });
+
       it('should resolve the file path with a known defined extension', () => {
         testWithImport(
           'rn',
           './test/testproject/src/rn/index.ios.js',
           rootTransformerOpts,
         );
       });
+
+
+      it('should resolve the relative file path with a known defined extension', () => {
+        testWithImport(
+          './test/testproject/src/rn/index',
+          './test/testproject/src/rn/index.ios.js',
+          rootTransformerOpts,
+        );
+      });
     });
 
     describe('root and alias', () => {