[FIX] npm t8r: Again, handle npm optionalDependencies correctly

Fixes the fix done in #60.

Fixes: #51

lib/translators/npm.js

@@ -33,25 +33,6 @@ class NpmTranslator {
 		let dependencies = pkg.dependencies || {};
 		let optDependencies = pkg.devDependencies || {};
 
-		// Due to normalization done by by the "read-pkg-up" module the values
-		//  in optionalDependencies get added to dependencies. Also as described here:
-		//  https://github.com/npm/normalize-package-data#what-normalization-currently-entails
-		// Note: optionalDependencies are treated the same as devDependencies in the npm translator
-		if (pkg.optionalDependencies) {
-			for (const depName in pkg.optionalDependencies) {
-				if (pkg.optionalDependencies.hasOwnProperty(depName)) {
-					// Remove entry from "hard" dependencies map
-					if (dependencies[depName]) {
-						delete dependencies[depName];
-					}
-					// Add to optional dependencies map (of not already done)
-					if (optDependencies.hasOwnProperty(depName)) {
-						optDependencies[depName] = pkg.optionalDependencies[depName];
-					}
-				}
-			}
-		}
-
 		const version = pkg.version;
 
 		// Also look for "napa" dependencies (see https://github.com/shama/napa)
@@ -96,7 +77,8 @@ class NpmTranslator {
 			return this.getDepProjects({
 				cwd,
 				parentName: moduleName,
-				dependencies
+				dependencies,
+				optionalDependencies: pkg.optionalDependencies
 			}).then((depProjects) => {
 				// Array needs to be flattened because:
 				// getDepProjects returns array * 2 = array with two arrays
@@ -141,11 +123,21 @@ class NpmTranslator {
 		}
 	}
 
-	getDepProjects({cwd, dependencies, parentName}) {
+	getDepProjects({cwd, dependencies, optionalDependencies, parentName}) {
 		return Promise.all(
 			Object.keys(dependencies).map((moduleName) => {
 				return this.findModulePath(cwd, moduleName).then((modulePath) => {
 					return this.readProject({modulePath, moduleName, parentName});
+				}, (err) => {
+					// Due to normalization done by by the "read-pkg-up" module the values
+					//  in optionalDependencies get added to dependencies. Also as described here:
+					//  https://github.com/npm/normalize-package-data#what-normalization-currently-entails
+					// Resolution errors of optionalDependencies are being ignored
+					if (optionalDependencies && optionalDependencies[moduleName]) {
+						return null;
+					} else {
+						throw err;
+					}
 				});
 			})
 		).then((depProjects) => {

test/fixtures/application.g/package.json

@@ -4,6 +4,7 @@
   "description": "Simple SAPUI5 based application - test for npm optionalDependencies",
   "main": "index.html",
   "optionalDependencies": {
+    "library.d": "file:../library.d",
     "library.nonexistent": "file:../library.nonexistent"
   },
   "scripts": {

test/lib/translators/npm.js

@@ -238,5 +238,12 @@ const applicationGTree = {
 	id: "application.g",
 	version: "1.0.0",
 	path: applicationGPath,
-	dependencies: []
+	dependencies: [
+		{
+			id: "library.d",
+			version: "1.0.0",
+			path: path.join(applicationGPath, "node_modules", "library.d"),
+			dependencies: []
+		}
+	]
 };