[Refactor] no-extraneous-dependencies improve performance using cache

Author: meowtec

src/rules/no-extraneous-dependencies.js

@@ -1,6 +1,6 @@
 import path from 'path';
 import fs from 'fs';
-import readPkgUp from 'eslint-module-utils/readPkgUp';
+import pkgUp from 'eslint-module-utils/pkgUp';
 import minimatch from 'minimatch';
 import resolve from 'eslint-module-utils/resolve';
 import moduleVisitor from 'eslint-module-utils/moduleVisitor';
@@ -30,6 +30,21 @@ function extractDepFields(pkg) {
   };
 }
 
+function getPackageDepFields(packageJsonPath) {
+  if (packageJsonPath && !depFieldCache.has(packageJsonPath)) {
+    let content;
+    try {
+      content = JSON.parse(fs.readFileSync(packageJsonPath, 'utf8'));
+    } catch (err) {
+      content = {};
+    }
+    const depFields = extractDepFields(content);
+    depFieldCache.set(packageJsonPath, depFields);
+  }
+
+  return depFieldCache.get(packageJsonPath);
+}
+
 function getDependencies(context, packageDir) {
   let paths = [];
   try {
@@ -53,24 +68,21 @@ function getDependencies(context, packageDir) {
       // use rule config to find package.json
       paths.forEach(dir => {
         const packageJsonPath = path.join(dir, 'package.json');
-        if (!depFieldCache.has(packageJsonPath)) {
-          const depFields = extractDepFields(
-            JSON.parse(fs.readFileSync(packageJsonPath, 'utf8')),
-          );
-          depFieldCache.set(packageJsonPath, depFields);
-        }
-        const _packageContent = depFieldCache.get(packageJsonPath);
+        const _packageContent = getPackageDepFields(packageJsonPath) || {};
         Object.keys(packageContent).forEach(depsKey =>
           Object.assign(packageContent[depsKey], _packageContent[depsKey]),
         );
       });
     } else {
+      const packageJsonPath = pkgUp({
+        cwd: context.getPhysicalFilename ? context.getPhysicalFilename() : context.getFilename(),
+        normalize: false,
+      });
+
       // use closest package.json
       Object.assign(
         packageContent,
-        extractDepFields(
-          readPkgUp({ cwd: context.getPhysicalFilename ? context.getPhysicalFilename() : context.getFilename(), normalize: false }).pkg,
-        ),
+        getPackageDepFields(packageJsonPath),
       );
     }