Try to use node resolution for module path

This will allow assets to be in external modules.
Issue #3

.gitignore

@@ -1,6 +1,7 @@
 # Binaries
 node_modules/
 dist/
+!__test__/node_modules
 
 # Coverage
 .nyc_output/

__test__/package/success.ts

@@ -0,0 +1,22 @@
+import * as pngImage from '../sub/folder/image.png'
+import svgImage from '../image.svg'
+import moduleImage from 'dummy/picture.svg'
+import defaultImage from '../reexport'
+import { image } from '../reexport'
+
+export default function getPath(
+  type: 'fullImport' | 'defaultImport' | 'moduleImport' | 'defaultExport' | 'namedExport'
+): string {
+  switch (type) {
+    case 'fullImport':
+      return pngImage
+    case 'defaultImport':
+      return svgImage
+    case 'moduleImport':
+      return moduleImage
+    case 'defaultExport':
+      return defaultImage
+    case 'namedExport':
+      return image
+  }
+}

__test__/success.ts

@@ -1,6 +1,6 @@
 import * as pngImage from './sub/folder/image.png'
 import svgImage from './image.svg'
-import moduleImage from 'module/image.svg'
+import moduleImage from 'dummy/picture.svg'
 import defaultImage from './reexport'
 import { image } from './reexport'
 

src/context/AssetModuleManager.ts

@@ -40,7 +40,7 @@ export default class AssetModuleManager {
 
       // Check if matching assets pattern
       if (this.assetsMatch.test(moduleName)) {
-        return this.interpolateName(moduleName)
+        return this.interpolateName(this.findModulePath(moduleName))
       }
     }
     return undefined
@@ -49,11 +49,10 @@ export default class AssetModuleManager {
   /**
    * Create the asset name using `targetName` template and given module name.
    *
-   * @param moduleName - The name of module to use as interpolation source.
+   * @param modulePath - The path of module to use as interpolation source.
    * @returns The asset name.
    */
-  private interpolateName(moduleName: string): string {
-    const modulePath = join(this.currentPath, moduleName)
+  private interpolateName(modulePath: string): string {
     const parsed = parse(modulePath)
     /* istanbul ignore next */
     const ext = parsed.ext ? parsed.ext.substr(1) : 'bin'
@@ -91,4 +90,20 @@ export default class AssetModuleManager {
       .replace(/\[folder\]/gi, folder)
     return url
   }
+
+  /**
+   * Find the module path, using default node resolution, or simply searching relative to current file.
+   *
+   * @param moduleName - The name of the module to find.
+   * @returns The module path.
+   */
+  private findModulePath(moduleName: string): string {
+    try {
+      return require.resolve(moduleName, {
+        paths: [this.basePath],
+      })
+    } catch {
+      return join(this.currentPath, moduleName)
+    }
+  }
 }

src/index.spec.ts

@@ -15,7 +15,7 @@ describe('ts-transform-asset', function () {
       result: {
         fullImport: string
         defaultImport: string
-        moduleImport: string
+        moduleImport: string | undefined
         defaultExport: string
         namedExport: string
       }
@@ -26,7 +26,7 @@ describe('ts-transform-asset', function () {
       result: {
         fullImport: 'image.png',
         defaultImport: 'image.svg',
-        moduleImport: 'image.svg',
+        moduleImport: 'picture.svg',
         defaultExport: 'image.svg',
         namedExport: 'image.svg',
       },
@@ -36,16 +36,17 @@ describe('ts-transform-asset', function () {
       result: {
         fullImport: 'assets/image.png',
         defaultImport: 'assets/image.svg',
-        moduleImport: 'assets/image.svg',
+        moduleImport: 'assets/picture.svg',
         defaultExport: 'assets/image.svg',
         namedExport: 'assets/image.svg',
       },
     },
     default: {
+      rootDir: '__test__',
       result: {
         fullImport: '[hash].png',
         defaultImport: 'b05767c238cb9f989cf3cd8180594878.svg',
-        moduleImport: '[hash].svg',
+        moduleImport: 'bee0f4fbbfd53e62289432b4a070cd03.svg',
         defaultExport: 'b05767c238cb9f989cf3cd8180594878.svg',
         namedExport: 'b05767c238cb9f989cf3cd8180594878.svg',
       },
@@ -56,7 +57,8 @@ describe('ts-transform-asset', function () {
       result: {
         fullImport: 'sub/folder/folder_[hash]-[contenthash].png',
         defaultImport: '_b05767c238cb9f989cf3cd8180594878-b05767c238cb9f989cf3cd8180594878.svg',
-        moduleImport: 'module/module_[hash]-[contenthash].svg',
+        moduleImport:
+          'node_modules/dummy/dummy_bee0f4fbbfd53e62289432b4a070cd03-bee0f4fbbfd53e62289432b4a070cd03.svg',
         defaultExport: '_b05767c238cb9f989cf3cd8180594878-b05767c238cb9f989cf3cd8180594878.svg',
         namedExport: '_b05767c238cb9f989cf3cd8180594878-b05767c238cb9f989cf3cd8180594878.svg',
       },
@@ -67,7 +69,7 @@ describe('ts-transform-asset', function () {
         fullImport: '__test__/sub/folder/folder_[hash]-[contenthash].png',
         defaultImport:
           '__test__/__test___b05767c238cb9f989cf3cd8180594878-b05767c238cb9f989cf3cd8180594878.svg',
-        moduleImport: '__test__/module/module_[hash]-[contenthash].svg',
+        moduleImport: undefined,
         defaultExport:
           '__test__/__test___b05767c238cb9f989cf3cd8180594878-b05767c238cb9f989cf3cd8180594878.svg',
         namedExport:
@@ -109,24 +111,30 @@ describe('ts-transform-asset', function () {
         result.print()
       })
 
-      it('should find full module import file', function () {
-        expect(result.requireContent('success')('fullImport')).to.equal(testCase.result.fullImport)
-      })
+      Array.of('success', 'package/success').forEach(file => {
+        describe(`...in file ${file}`, function () {
+          it('should find full module import file', function () {
+            expect(result.requireContent(file)('fullImport')).to.equal(testCase.result.fullImport)
+          })
 
-      it('should find default module import file', function () {
-        expect(result.requireContent('success')('defaultImport')).to.equal(testCase.result.defaultImport)
-      })
+          it('should find default module import file', function () {
+            expect(result.requireContent(file)('defaultImport')).to.equal(testCase.result.defaultImport)
+          })
 
-      it('should find external module file', function () {
-        expect(result.requireContent('success')('moduleImport')).to.equal(testCase.result.moduleImport)
-      })
+          if (testCase.result.moduleImport) {
+            it('should find external module file', function () {
+              expect(result.requireContent(file)('moduleImport')).to.equal(testCase.result.moduleImport)
+            })
+          }
 
-      it('should find default re-exported file', function () {
-        expect(result.requireContent('success')('defaultExport')).to.equal(testCase.result.defaultExport)
-      })
+          it('should find default re-exported file', function () {
+            expect(result.requireContent(file)('defaultExport')).to.equal(testCase.result.defaultExport)
+          })
 
-      it('should find named re-exported file', function () {
-        expect(result.requireContent('success')('namedExport')).to.equal(testCase.result.namedExport)
+          it('should find named re-exported file', function () {
+            expect(result.requireContent(file)('namedExport')).to.equal(testCase.result.namedExport)
+          })
+        })
       })
 
       it('should fail to require bad module', function () {