text: "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 OPTION_SINGLE_CONCAT = "allow-single-concat";
  var Rule = (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, function (ctx) { return walk(ctx, allowSingleConcat); });
      };
      /* tslint:disable:object-literal-sort-keys */
      Rule.metadata = {
          ruleName: "prefer-template",
          description: "Prefer a template expression over string literal concatenation.",
          optionsDescription: (_a = ["\n            If `", "` is specified, then a single concatenation (`x + y`) is allowed, but not more (`x + y + z`)."], _a.raw = ["\n            If \\`", "\\` is specified, then a single concatenation (\\`x + y\\`) is allowed, but not more (\\`x + y + z\\`)."], Lint.Utils.dedent(_a, OPTION_SINGLE_CONCAT)),
          options: {
              type: "string",
              enum: [OPTION_SINGLE_CONCAT],
          },
          optionExamples: [true, [true, OPTION_SINGLE_CONCAT]],
          type: "style",
          typescriptOnly: false,
      };
      /* 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, 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 _a;
  