restrictPlusOperandsRule.js 4.4 KB
"use strict";
/**
 * @license
 * Copyright 2018 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 });
exports.Rule = void 0;
var tslib_1 = require("tslib");
var tsutils_1 = require("tsutils");
var ts = require("typescript");
var Lint = require("../index");
var Rule = /** @class */ (function (_super) {
    tslib_1.__extends(Rule, _super);
    function Rule() {
        return _super !== null && _super.apply(this, arguments) || this;
    }
    Rule.prototype.applyWithProgram = function (sourceFile, program) {
        return this.applyWithFunction(sourceFile, walk, undefined, program.getTypeChecker());
    };
    /* tslint:disable:object-literal-sort-keys */
    Rule.metadata = {
        ruleName: "restrict-plus-operands",
        description: "When adding two variables, operands must both be of type number or of type string.",
        optionsDescription: "Not configurable.",
        options: null,
        optionExamples: [true],
        type: "functionality",
        typescriptOnly: false,
        requiresTypeInfo: true,
    };
    /* tslint:enable:object-literal-sort-keys */
    Rule.INVALID_TYPES_ERROR = "Operands of '+' operation must either be both strings or both numbers or both bigints";
    Rule.SUGGEST_TEMPLATE_LITERALS = ". Consider using template literals.";
    return Rule;
}(Lint.Rules.TypedRule));
exports.Rule = Rule;
function walk(ctx, tc) {
    return ts.forEachChild(ctx.sourceFile, function cb(node) {
        if (tsutils_1.isBinaryExpression(node) && node.operatorToken.kind === ts.SyntaxKind.PlusToken) {
            var leftType = tc.getTypeAtLocation(node.left);
            var leftTypeStr = getBaseTypeOfLiteralType(leftType);
            var rightType = tc.getTypeAtLocation(node.right);
            var rightTypeStr = getBaseTypeOfLiteralType(rightType);
            if (leftTypeStr === "invalid" ||
                rightTypeStr === "invalid" ||
                leftTypeStr !== rightTypeStr) {
                var actualTypes = ", but found " + getTypeString(tc, node.left, leftType) + " + " + getTypeString(tc, node.right, rightType);
                var message = Rule.INVALID_TYPES_ERROR + actualTypes;
                if (leftTypeStr === "string" || rightTypeStr === "string") {
                    message += Rule.SUGGEST_TEMPLATE_LITERALS;
                }
                return ctx.addFailureAtNode(node, message);
            }
        }
        return ts.forEachChild(node, cb);
    });
}
function getTypeString(tc, node, type) {
    var typeString = tc.typeToString(type, node);
    if (typeString === "undefined[]" &&
        ts.isArrayLiteralExpression(node) &&
        node.elements.length === 0) {
        // Special case literal "[]" arrays that would otherwise be emitted as undefined[].
        return "[]";
    }
    return typeString;
}
function getBaseTypeOfLiteralType(type) {
    if (tsutils_1.isTypeFlagSet(type, ts.TypeFlags.StringLiteral) ||
        tsutils_1.isTypeFlagSet(type, ts.TypeFlags.String)) {
        return "string";
    }
    else if (tsutils_1.isTypeFlagSet(type, ts.TypeFlags.NumberLiteral) ||
        tsutils_1.isTypeFlagSet(type, ts.TypeFlags.Number)) {
        return "number";
    }
    else if (tsutils_1.isTypeFlagSet(type, ts.TypeFlags.BigIntLiteral) ||
        tsutils_1.isTypeFlagSet(type, ts.TypeFlags.BigInt)) {
        return "bigint";
    }
    else if (tsutils_1.isUnionType(type) && !tsutils_1.isTypeFlagSet(type, ts.TypeFlags.Enum)) {
        var types = type.types.map(getBaseTypeOfLiteralType);
        return allSame(types) ? types[0] : "invalid";
    }
    else if (tsutils_1.isTypeFlagSet(type, ts.TypeFlags.EnumLiteral)) {
        // Compatibility for TypeScript pre-2.4, which used EnumLiteralType instead of LiteralType
        getBaseTypeOfLiteralType(type.baseType);
    }
    return "invalid";
}
function allSame(array) {
    return array.every(function (value) { return value === array[0]; });
}