"use strict"; /** * @license * Copyright 2017 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. */ Object.defineProperty(exports, "__esModule", { value: true }); var tslib_1 = require("tslib"); var tsutils_1 = require("tsutils"); var ts = require("typescript"); var Lint = require("../index"); var preferTemplate_examples_1 = require("./code-examples/preferTemplate.examples"); var OPTION_SINGLE_CONCAT = "allow-single-concat"; var Rule = /** @class */ (function (_super) { tslib_1.__extends(Rule, _super); function Rule() { return _super !== null && _super.apply(this, arguments) || this; } Rule.prototype.apply = function (sourceFile) { if (sourceFile.isDeclarationFile) { return []; // Not possible in a declaration file } var allowSingleConcat = this.ruleArguments.indexOf(OPTION_SINGLE_CONCAT) !== -1; return this.applyWithFunction(sourceFile, walk, { allowSingleConcat: allowSingleConcat }); }; /* tslint:disable:object-literal-sort-keys */ Rule.metadata = { ruleName: "prefer-template", description: "Prefer a template expression over string literal concatenation.", optionsDescription: Lint.Utils.dedent(templateObject_1 || (templateObject_1 = tslib_1.__makeTemplateObject(["\n If `", "` is specified, then a single concatenation (`x + y`) is allowed, but not more (`x + y + z`)."], ["\n If \\`", "\\` is specified, then a single concatenation (\\`x + y\\`) is allowed, but not more (\\`x + y + z\\`)."])), OPTION_SINGLE_CONCAT), options: { type: "string", enum: [OPTION_SINGLE_CONCAT], }, optionExamples: [true, [true, OPTION_SINGLE_CONCAT]], type: "style", typescriptOnly: false, codeExamples: preferTemplate_examples_1.codeExamples, }; /* tslint:enable:object-literal-sort-keys */ Rule.FAILURE_STRING = "Use a template literal instead of concatenating with a string literal."; Rule.FAILURE_STRING_MULTILINE = "Use a multiline template literal instead of concatenating string literals with newlines."; return Rule; }(Lint.Rules.AbstractRule)); exports.Rule = Rule; function walk(ctx) { var allowSingleConcat = ctx.options.allowSingleConcat; return ts.forEachChild(ctx.sourceFile, function cb(node) { var failure = getError(node, allowSingleConcat); if (failure !== undefined) { ctx.addFailureAtNode(node, failure); } else { return ts.forEachChild(node, cb); } }); } function getError(node, allowSingleConcat) { if (!isPlusExpression(node)) { return undefined; } var left = node.left, right = node.right; var l = isStringLike(left); var r = isStringLike(right); if (l && r) { // They're both strings. // If they're joined by a newline, recommend a template expression instead. // Otherwise ignore. ("a" + "b", probably writing a long newline-less string on many lines.) return containsNewline(left) || containsNewline(right) ? Rule.FAILURE_STRING_MULTILINE : undefined; } else if (!l && !r) { // Watch out for `"a" + b + c`. Parsed as `("a" + b) + c`. return containsAnyStringLiterals(left) ? Rule.FAILURE_STRING : undefined; } else if (l) { // `"x" + y` return !allowSingleConcat ? Rule.FAILURE_STRING : undefined; } else { // `? + "b"` // If LHS consists of only string literals (as in `"a" + "b" + "c"`, allow it.) return !containsOnlyStringLiterals(left) && (!allowSingleConcat || isPlusExpression(left)) ? Rule.FAILURE_STRING : undefined; } } function containsNewline(node) { if (node.kind === ts.SyntaxKind.TemplateExpression) { return node.templateSpans.some(function (_a) { var text = _a.literal.text; return text.includes("\n"); }); } else { return node.text.includes("\n"); } } function containsOnlyStringLiterals(node) { return (isPlusExpression(node) && isStringLike(node.right) && (isStringLike(node.left) || containsAnyStringLiterals(node.left))); } function containsAnyStringLiterals(node) { return (isPlusExpression(node) && (isStringLike(node.right) || isStringLike(node.left) || containsAnyStringLiterals(node.left))); } function isPlusExpression(node) { return tsutils_1.isBinaryExpression(node) && node.operatorToken.kind === ts.SyntaxKind.PlusToken; } function isStringLike(node) { switch (node.kind) { case ts.SyntaxKind.StringLiteral: case ts.SyntaxKind.NoSubstitutionTemplateLiteral: case ts.SyntaxKind.TemplateExpression: return true; default: return false; } } var templateObject_1;