Implement 'no-default-import' rule

src/rules/noDefaultImportRule.ts

@@ -0,0 +1,105 @@
+/**
+ * @license
+ * Copyright 2016 Palantir Technologies, Inc.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { isImportDeclaration, isNamedImports, isStringLiteral } from "tsutils";
+import * as ts from "typescript";
+import * as Lint from "../index";
+
+const fromModulesConfigOptionName = "fromModules";
+interface Options {
+ [fromModulesConfigOptionName]: RegExp;
+}
+
+export class Rule extends Lint.Rules.AbstractRule {
+ /* tslint:disable:object-literal-sort-keys */
+ public static metadata: Lint.IRuleMetadata = {
+ ruleName: "no-default-import",
+ description: "Disallows importing default members from certain ES6-style modules.",
+ descriptionDetails: "Import named members instead.",
+ rationale: Lint.Utils.dedent`
+ Named imports/exports [promote clarity](https://github.com/palantir/tslint/issues/1182#issue-151780453).
+ In addition, current tooling differs on the correct way to handle default imports/exports.
+ Avoiding them all together can help avoid tooling bugs and conflicts.
+
+ While "no-default-import" ???????`,
+ optionsDescription: "optionsDescription",
+ options: {
+ type: "object",
+ required: [fromModulesConfigOptionName],
+ properties: {
+ [fromModulesConfigOptionName]: { type: "string" },
+ },
+ },
+ optionExamples: [
+ [true, { [fromModulesConfigOptionName]: "^palantir-|_internal-*" }],
+ ],
+ type: "maintainability",
+ typescriptOnly: false,
+ };
+ /* tslint:enable:object-literal-sort-keys */
+
+ public static FAILURE_STRING = "Import of default members from this module is forbidden. Import named member instead";
+
+ public static getNamedDefaultImport(namedBindings: ts.NamedImports): ts.Identifier | null {
+ for (const importSpecifier of namedBindings.elements) {
+ if (importSpecifier.propertyName && importSpecifier.propertyName.text === "default") {
+ return importSpecifier.propertyName;
+ }
+ }
+ return null;
+ }
+
+ public apply(sourceFile: ts.SourceFile): Lint.RuleFailure[] {
+ return this.applyWithFunction(sourceFile, walk, this.getRuleOptions());
+ }
+ private getRuleOptions(): Options {
+ const ruleArguments: Partial<Options> = this.ruleArguments[0];
+ const fromModules = ruleArguments[fromModulesConfigOptionName];
+ return {
+ [fromModulesConfigOptionName]: new RegExp(fromModules || ""),
+ };
+ }
+}
+
+function walk(ctx: Lint.WalkContext<Options>) {
+ if (ctx.sourceFile.isDeclarationFile || !ts.isExternalModule(ctx.sourceFile)) {
+ return;
+ }
+ for (const statement of ctx.sourceFile.statements) {
+ if (isImportDeclaration(statement)) {
+ const { importClause, moduleSpecifier } = statement;
+ if (
+ importClause
+ && isStringLiteral(moduleSpecifier)
+ && ctx.options[fromModulesConfigOptionName].test(moduleSpecifier.text)
+ ) {
+ // module name matches specified in rule config
+ if (importClause.name) {
+ // `import Foo...` syntax
+ const defaultImportedName = importClause.name;
+ ctx.addFailureAtNode(defaultImportedName, Rule.FAILURE_STRING);
+ } else if (importClause.namedBindings && isNamedImports(importClause.namedBindings)) {
+ // `import { default...` syntax
+ const defaultMember = Rule.getNamedDefaultImport(importClause.namedBindings);
+ if (defaultMember) {
+ ctx.addFailureAtNode(defaultMember, Rule.FAILURE_STRING);
+ }
+ }
+ }
+ }
+ }
+}

test/rules/no-default-import/test.ts.lint

@@ -0,0 +1,21 @@
+import * from "tslint-utils"
+
+import TslintUtils from "tslint-utils"
+ ~~~~~~~~~~~ [0]
+
+import Bar, { Foo } from "tslint-misc"
+ ~~~ [0]
+
+import Bar, * as Foo from "tslint-misc"
+ ~~~ [0]
+
+import { default as Foo } from "tslint-misc"
+ ~~~~~~~ [0]
+
+import { default as foo, bar } from "tslint-misc"
+ ~~~~~~~ [0]
+
+import { bar, default as foo } from "tslint-misc"
+ ~~~~~~~ [0]
+
+[0]: Import of default members from this module is forbidden. Import named member instead

test/rules/no-default-import/tslint.json

@@ -0,0 +1,7 @@
+{
+ "rules": {
+ "no-default-import": [true, {
+ "fromModules": "^tslint-"
+ }]
+ }
+}