feat(dev): add loglevel to configure console logging (#351)

DOCS.md

@@ -203,6 +203,23 @@ module.exports = {
 
 If you want to leave some paths as-is, then you can return `undefined` or any other falsy value from the function.
 
+## loglevel
+
+One of the [NPM log level options](https://docs.npmjs.com/misc/config#loglevel) to configure console logging during build. Default is `"warn"`. Passing `"silent"` will disable all warnings for path resolution failures.
+
+```js
+module.exports = {
+  plugins: [
+    ["module-resolver", {
+      alias: {
+        "dependency-string": "module-that-does-not-exist" // warning will not log
+      },
+      loglevel: 'silent'
+    }]
+  ]
+}
+```
+
 # Usage with create-react-app
 
 create-react-app by default don't use .babelrc, so in webpack.config.dev.js, add plugins property within js loader like below. Note that plugins recieve an array.

src/normalizeOptions.js

@@ -132,6 +132,10 @@ function normalizeTransformedFunctions(optsTransformFunctions) {
   return [...defaultTransformedFunctions, ...optsTransformFunctions];
 }
 
+function normalizeLoglevel(optsLoglevel) {
+  return optsLoglevel || 'warn';
+}
+
 export default createSelector(
   // The currentFile should have an extension; otherwise it's considered a special value
   currentFile => (currentFile.includes('.') ? path.dirname(currentFile) : currentFile),
@@ -140,6 +144,7 @@ export default createSelector(
     const cwd = normalizeCwd(opts.cwd, currentFile);
     const root = normalizeRoot(opts.root, cwd);
     const alias = normalizeAlias(opts.alias);
+    const loglevel = normalizeLoglevel(opts.loglevel);
     const transformFunctions = normalizeTransformedFunctions(opts.transformFunctions);
     const extensions = opts.extensions || defaultExtensions;
     const stripExtensions = opts.stripExtensions || extensions;
@@ -149,6 +154,7 @@ export default createSelector(
       cwd,
       root,
       alias,
+      loglevel,
       transformFunctions,
       extensions,
       stripExtensions,

src/resolvePath.js

@@ -39,9 +39,9 @@ function resolvePathFromRootConfig(sourcePath, currentFile, opts) {
   return getRelativePath(sourcePath, currentFile, absFileInRoot, opts);
 }
 
-function checkIfPackageExists(modulePath, currentFile, extensions) {
+function checkIfPackageExists(modulePath, currentFile, extensions, loglevel) {
   const resolvedPath = nodeResolvePath(modulePath, currentFile, extensions);
-  if (resolvedPath === null) {
+  if (resolvedPath === null && loglevel !== 'silent') {
     warn(`Could not resolve "${modulePath}" in file ${currentFile}.`);
   }
 }
@@ -71,7 +71,7 @@ function resolvePathFromAliasConfig(sourcePath, currentFile, opts) {
   }
 
   if (process.env.NODE_ENV !== 'production') {
-    checkIfPackageExists(aliasedSourceFile, currentFile, opts.extensions);
+    checkIfPackageExists(aliasedSourceFile, currentFile, opts.extensions, opts.loglevel);
   }
 
   return aliasedSourceFile;

test/index.test.js

@@ -685,6 +685,28 @@ describe('module-resolver', () => {
           expect(mockWarn.mock.calls.length).toBe(0);
         });
       });
+
+      const silentLoggingOpts = {
+        babelrc: false,
+        plugins: [
+          [pluginWithMock, {
+            alias: {
+              legacy: 'npm:legacy',
+              'non-existing': 'this-package-does-not-exist',
+            },
+            loglevel: 'silent',
+          }],
+        ],
+      };
+
+      it('should respect opt loglevel:silent', () => {
+        testWithImport(
+          'legacy/lib',
+          'npm:legacy/lib',
+          silentLoggingOpts,
+        );
+          expect(mockWarn.mock.calls.length).toBe(0);
+      });
     });
 
     describe('multiple alias application', () => {