add eslint plugin for checking imports (prebid#3976)

.eslintrc.js

@@ -1,3 +1,13 @@
+
+const sharedWhiteList = [
+  "core-js/library/fn/array/find", // no ie11
+  "core-js/library/fn/array/includes", // no ie11
+  "core-js/library/fn/set", // ie11 supports Set but not Set#values
+  "core-js/library/fn/string/includes", // no ie11
+  "core-js/library/fn/number/is-integer", // no ie11,
+  "core-js/library/fn/array/from" // no ie11
+];
+
 module.exports = {
   "env": {
     "browser": true,
@@ -11,6 +21,9 @@ module.exports = {
     }
   },
   "extends": "standard",
+  "plugins": [
+    "prebid"
+  ],
   "globals": {
     "$$PREBID_GLOBAL$$": false
   },
@@ -31,5 +44,24 @@ module.exports = {
     "no-throw-literal": "off",
     "no-undef": "off",
     "no-useless-escape": "off",
-  }
+  },
+  "overrides": [{
+    "files": "modules/**/*.js",
+    "rules": {
+      "prebid/validate-imports": ["error", [
+        ...sharedWhiteList,
+        "jsencrypt",
+        "crypto-js"
+      ]]
+    }
+  }, {
+    "files": "src/**/*.js",
+    "rules": {
+      "prebid/validate-imports": ["error", [
+        ...sharedWhiteList,
+        "fun-hooks/no-eval",
+        "just-clone"
+      ]]
+    }
+  }]
 };

modules/ixBidAdapter.js

@@ -1,7 +1,6 @@
 import * as utils from '../src/utils';
 import { BANNER } from '../src/mediaTypes';
 import { config } from '../src/config';
-import isArray from 'core-js/library/fn/array/is-array';
 import isInteger from 'core-js/library/fn/number/is-integer';
 import { registerBidder } from '../src/adapters/bidderFactory';
 
@@ -92,7 +91,7 @@ function parseBid(rawBid, currency) {
  * @return {boolean}      True if this is a valid size format, and false otherwise.
  */
 function isValidSize(size) {
-  return isArray(size) && size.length === 2 && isInteger(size[0]) && isInteger(size[1]);
+  return Array.isArray(size) && size.length === 2 && isInteger(size[0]) && isInteger(size[1]);
 }
 
 /**

package.json

@@ -37,6 +37,7 @@
     "eslint-plugin-node": "^5.1.0",
     "eslint-plugin-promise": "^3.5.0",
     "eslint-plugin-standard": "^3.0.1",
+    "eslint-plugin-prebid": "file:./plugins/eslint",
     "execa": "^1.0.0",
     "faker": "^3.1.0",
     "fs.extra": "^1.3.2",
@@ -79,6 +80,7 @@
     "mocha": "^5.0.0",
     "opn": "^5.4.0",
     "querystringify": "0.0.3",
+    "resolve-from": "^5.0.0",
     "sinon": "^4.1.3",
     "through2": "^2.0.3",
     "url-parse": "^1.0.5",

plugins/eslint/package.json

@@ -0,0 +1,8 @@
+{
+  "name": "eslint-plugin-prebid",
+  "version": "1.0.0",
+  "description": "validates module imports can be found without custom webpack resolvers, are in module whitelist, and not module entry points",
+  "main": "validateImports.js",
+  "author": "the prebid.js contributors",
+  "license": "Apache-2.0"
+}

plugins/eslint/validateImports.js

@@ -0,0 +1,61 @@
+
+let path = require('path');
+let _ = require('lodash');
+let resolveFrom = require('resolve-from');
+
+function flagErrors(context, node, importPath) {
+  let absFileDir = path.dirname(context.getFilename());
+  let absImportPath = path.resolve(absFileDir, importPath);
+
+  try {
+    resolveFrom(absFileDir, importPath);
+  } catch (e) {
+    return context.report(node, `import "${importPath}" cannot be resolved`);
+  }
+
+  if (
+    Array.isArray(_.get(context, ['options', 0])) &&
+    importPath.match(/^\w+/) &&
+    !context.options[0].some(name => importPath.startsWith(name))
+  ) {
+    context.report(node, `import "${importPath}" not in import whitelist`);
+  } else {
+    let absModulePath = path.resolve(__dirname, '../../modules');
+
+    // don't allow import of any files directly within modules folder or index.js files within modules' sub-folders
+    if (
+      path.dirname(absImportPath) === absModulePath || (
+        absImportPath.startsWith(absModulePath) &&
+        path.basename(absImportPath) === 'index.js'
+      )
+    ) {
+      context.report(node, `import "${importPath}" cannot require module entry point`);
+    }
+  }
+}
+
+module.exports = {
+  rules: {
+    'validate-imports': {
+      meta: {
+        docs: {
+          description: 'validates module imports can be found without custom webpack resolvers, are in module whitelist, and not module entry points'
+        }
+      },
+      create: function(context) {
+        return {
+          "CallExpression[callee.name='require']"(node) {
+            let importPath = _.get(node, ['arguments', 0, 'value']);
+            if (importPath) {
+              flagErrors(context, node, importPath);
+            }
+          },
+          ImportDeclaration(node) {
+            let importPath = node.source.value.trim();
+            flagErrors(context, node, importPath);
+          }
+        }
+      }
+    }
+  }
+};

src/adapters/analytics/example2.js

@@ -1,4 +1,4 @@
-import { ajax } from 'src/ajax';
+import { ajax } from '../../../src/ajax';
 
 /**
  * example2.js - analytics adapter for Example2 Analytics Endpoint example