| "use strict"; |
| var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { |
| if (k2 === undefined) k2 = k; |
| Object.defineProperty(o, k2, { enumerable: true, get: function() { return m[k]; } }); |
| }) : (function(o, m, k, k2) { |
| if (k2 === undefined) k2 = k; |
| o[k2] = m[k]; |
| })); |
| var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) { |
| Object.defineProperty(o, "default", { enumerable: true, value: v }); |
| }) : function(o, v) { |
| o["default"] = v; |
| }); |
| var __importStar = (this && this.__importStar) || function (mod) { |
| if (mod && mod.__esModule) return mod; |
| var result = {}; |
| if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); |
| __setModuleDefault(result, mod); |
| return result; |
| }; |
| Object.defineProperty(exports, "__esModule", { value: true }); |
| const utils_1 = require("@typescript-eslint/utils"); |
| const tsutils = __importStar(require("tsutils")); |
| const ts = __importStar(require("typescript")); |
| const util = __importStar(require("../util")); |
| exports.default = util.createRule({ |
| name: 'strict-boolean-expressions', |
| meta: { |
| type: 'suggestion', |
| fixable: 'code', |
| hasSuggestions: true, |
| docs: { |
| description: 'Restricts the types allowed in boolean expressions', |
| recommended: false, |
| requiresTypeChecking: true, |
| }, |
| schema: [ |
| { |
| type: 'object', |
| properties: { |
| allowString: { type: 'boolean' }, |
| allowNumber: { type: 'boolean' }, |
| allowNullableObject: { type: 'boolean' }, |
| allowNullableBoolean: { type: 'boolean' }, |
| allowNullableString: { type: 'boolean' }, |
| allowNullableNumber: { type: 'boolean' }, |
| allowAny: { type: 'boolean' }, |
| allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing: { |
| type: 'boolean', |
| }, |
| }, |
| additionalProperties: false, |
| }, |
| ], |
| messages: { |
| conditionErrorOther: 'Unexpected value in conditional. ' + |
| 'A boolean expression is required.', |
| conditionErrorAny: 'Unexpected any value in conditional. ' + |
| 'An explicit comparison or type cast is required.', |
| conditionErrorNullish: 'Unexpected nullish value in conditional. ' + |
| 'The condition is always false.', |
| conditionErrorNullableBoolean: 'Unexpected nullable boolean value in conditional. ' + |
| 'Please handle the nullish case explicitly.', |
| conditionErrorString: 'Unexpected string value in conditional. ' + |
| 'An explicit empty string check is required.', |
| conditionErrorNullableString: 'Unexpected nullable string value in conditional. ' + |
| 'Please handle the nullish/empty cases explicitly.', |
| conditionErrorNumber: 'Unexpected number value in conditional. ' + |
| 'An explicit zero/NaN check is required.', |
| conditionErrorNullableNumber: 'Unexpected nullable number value in conditional. ' + |
| 'Please handle the nullish/zero/NaN cases explicitly.', |
| conditionErrorObject: 'Unexpected object value in conditional. ' + |
| 'The condition is always true.', |
| conditionErrorNullableObject: 'Unexpected nullable object value in conditional. ' + |
| 'An explicit null check is required.', |
| noStrictNullCheck: 'This rule requires the `strictNullChecks` compiler option to be turned on to function correctly.', |
| conditionFixDefaultFalse: 'Explicitly treat nullish value the same as false (`value ?? false`)', |
| conditionFixDefaultEmptyString: 'Explicitly treat nullish value the same as an empty string (`value ?? ""`)', |
| conditionFixDefaultZero: 'Explicitly treat nullish value the same as 0 (`value ?? 0`)', |
| conditionFixCompareNullish: 'Change condition to check for null/undefined (`value != null`)', |
| conditionFixCastBoolean: 'Explicitly cast value to a boolean (`Boolean(value)`)', |
| conditionFixCompareTrue: 'Change condition to check if true (`value === true`)', |
| conditionFixCompareFalse: 'Change condition to check if false (`value === false`)', |
| conditionFixCompareStringLength: "Change condition to check string's length (`value.length !== 0`)", |
| conditionFixCompareEmptyString: 'Change condition to check for empty string (`value !== ""`)', |
| conditionFixCompareZero: 'Change condition to check for 0 (`value !== 0`)', |
| conditionFixCompareNaN: 'Change condition to check for NaN (`!Number.isNaN(value)`)', |
| }, |
| }, |
| defaultOptions: [ |
| { |
| allowString: true, |
| allowNumber: true, |
| allowNullableObject: true, |
| allowNullableBoolean: false, |
| allowNullableString: false, |
| allowNullableNumber: false, |
| allowAny: false, |
| allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing: false, |
| }, |
| ], |
| create(context, [options]) { |
| const parserServices = util.getParserServices(context); |
| const typeChecker = parserServices.program.getTypeChecker(); |
| const compilerOptions = parserServices.program.getCompilerOptions(); |
| const sourceCode = context.getSourceCode(); |
| const isStrictNullChecks = tsutils.isStrictCompilerOptionEnabled(compilerOptions, 'strictNullChecks'); |
| if (!isStrictNullChecks && |
| options.allowRuleToRunWithoutStrictNullChecksIKnowWhatIAmDoing !== true) { |
| context.report({ |
| loc: { |
| start: { line: 0, column: 0 }, |
| end: { line: 0, column: 0 }, |
| }, |
| messageId: 'noStrictNullCheck', |
| }); |
| } |
| const checkedNodes = new Set(); |
| return { |
| ConditionalExpression: checkTestExpression, |
| DoWhileStatement: checkTestExpression, |
| ForStatement: checkTestExpression, |
| IfStatement: checkTestExpression, |
| WhileStatement: checkTestExpression, |
| 'LogicalExpression[operator!="??"]': checkNode, |
| 'UnaryExpression[operator="!"]': checkUnaryLogicalExpression, |
| }; |
| function checkTestExpression(node) { |
| if (node.test == null) { |
| return; |
| } |
| checkNode(node.test, true); |
| } |
| function checkUnaryLogicalExpression(node) { |
| checkNode(node.argument, true); |
| } |
| /** |
| * This function analyzes the type of a node and checks if it is allowed in a boolean context. |
| * It can recurse when checking nested logical operators, so that only the outermost operands are reported. |
| * The right operand of a logical expression is ignored unless it's a part of a test expression (if/while/ternary/etc). |
| * @param node The AST node to check. |
| * @param isTestExpr Whether the node is a descendant of a test expression. |
| */ |
| function checkNode(node, isTestExpr = false) { |
| // prevent checking the same node multiple times |
| if (checkedNodes.has(node)) { |
| return; |
| } |
| checkedNodes.add(node); |
| // for logical operator, we check its operands |
| if (node.type === utils_1.AST_NODE_TYPES.LogicalExpression && |
| node.operator !== '??') { |
| checkNode(node.left, isTestExpr); |
| // we ignore the right operand when not in a context of a test expression |
| if (isTestExpr) { |
| checkNode(node.right, isTestExpr); |
| } |
| return; |
| } |
| const tsNode = parserServices.esTreeNodeToTSNodeMap.get(node); |
| const type = util.getConstrainedTypeAtLocation(typeChecker, tsNode); |
| const types = inspectVariantTypes(tsutils.unionTypeParts(type)); |
| const is = (...wantedTypes) => types.size === wantedTypes.length && |
| wantedTypes.every(type => types.has(type)); |
| // boolean |
| if (is('boolean') || is('truthy boolean')) { |
| // boolean is always okay |
| return; |
| } |
| // never |
| if (is('never')) { |
| // never is always okay |
| return; |
| } |
| // nullish |
| if (is('nullish')) { |
| // condition is always false |
| context.report({ node, messageId: 'conditionErrorNullish' }); |
| return; |
| } |
| // Known edge case: boolean `true` and nullish values are always valid boolean expressions |
| if (is('nullish', 'truthy boolean')) { |
| return; |
| } |
| // nullable boolean |
| if (is('nullish', 'boolean')) { |
| if (!options.allowNullableBoolean) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!nullableBoolean) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableBoolean', |
| suggest: [ |
| { |
| messageId: 'conditionFixDefaultFalse', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? false`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCompareFalse', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} === false`, |
| }), |
| }, |
| ], |
| }); |
| } |
| else { |
| // if (nullableBoolean) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableBoolean', |
| suggest: [ |
| { |
| messageId: 'conditionFixDefaultFalse', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? false`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCompareTrue', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} === true`, |
| }), |
| }, |
| ], |
| }); |
| } |
| } |
| return; |
| } |
| // Known edge case: truthy primitives and nullish values are always valid boolean expressions |
| if ((options.allowNumber && is('nullish', 'truthy number')) || |
| (options.allowString && is('nullish', 'truthy string'))) { |
| return; |
| } |
| // string |
| if (is('string') || is('truthy string')) { |
| if (!options.allowString) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!string) |
| context.report({ |
| node, |
| messageId: 'conditionErrorString', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareStringLength', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code}.length === 0`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCompareEmptyString', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} === ""`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `!Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| else { |
| // if (string) |
| context.report({ |
| node, |
| messageId: 'conditionErrorString', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareStringLength', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code}.length > 0`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCompareEmptyString', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} !== ""`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| } |
| return; |
| } |
| // nullable string |
| if (is('nullish', 'string')) { |
| if (!options.allowNullableString) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!nullableString) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableString', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareNullish', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} == null`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixDefaultEmptyString', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? ""`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `!Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| else { |
| // if (nullableString) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableString', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareNullish', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} != null`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixDefaultEmptyString', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? ""`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| } |
| return; |
| } |
| // number |
| if (is('number') || is('truthy number')) { |
| if (!options.allowNumber) { |
| if (isArrayLengthExpression(node, typeChecker, parserServices)) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!array.length) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNumber', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} === 0`, |
| }), |
| }); |
| } |
| else { |
| // if (array.length) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNumber', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} > 0`, |
| }), |
| }); |
| } |
| } |
| else if (isLogicalNegationExpression(node.parent)) { |
| // if (!number) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNumber', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareZero', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| // TODO: we have to compare to 0n if the type is bigint |
| wrap: code => `${code} === 0`, |
| }), |
| }, |
| { |
| // TODO: don't suggest this for bigint because it can't be NaN |
| messageId: 'conditionFixCompareNaN', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `Number.isNaN(${code})`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `!Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| else { |
| // if (number) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNumber', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareZero', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} !== 0`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCompareNaN', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `!Number.isNaN(${code})`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| } |
| return; |
| } |
| // nullable number |
| if (is('nullish', 'number')) { |
| if (!options.allowNullableNumber) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!nullableNumber) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableNumber', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareNullish', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} == null`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixDefaultZero', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? 0`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `!Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| else { |
| // if (nullableNumber) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableNumber', |
| suggest: [ |
| { |
| messageId: 'conditionFixCompareNullish', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} != null`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixDefaultZero', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} ?? 0`, |
| }), |
| }, |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| } |
| return; |
| } |
| // object |
| if (is('object')) { |
| // condition is always true |
| context.report({ node, messageId: 'conditionErrorObject' }); |
| return; |
| } |
| // nullable object |
| if (is('nullish', 'object')) { |
| if (!options.allowNullableObject) { |
| if (isLogicalNegationExpression(node.parent)) { |
| // if (!nullableObject) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableObject', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node: node.parent, |
| innerNode: node, |
| wrap: code => `${code} == null`, |
| }), |
| }); |
| } |
| else { |
| // if (nullableObject) |
| context.report({ |
| node, |
| messageId: 'conditionErrorNullableObject', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `${code} != null`, |
| }), |
| }); |
| } |
| } |
| return; |
| } |
| // any |
| if (is('any')) { |
| if (!options.allowAny) { |
| context.report({ |
| node, |
| messageId: 'conditionErrorAny', |
| suggest: [ |
| { |
| messageId: 'conditionFixCastBoolean', |
| fix: util.getWrappingFixer({ |
| sourceCode, |
| node, |
| wrap: code => `Boolean(${code})`, |
| }), |
| }, |
| ], |
| }); |
| } |
| return; |
| } |
| // other |
| context.report({ node, messageId: 'conditionErrorOther' }); |
| } |
| /** |
| * Check union variants for the types we care about |
| */ |
| function inspectVariantTypes(types) { |
| const variantTypes = new Set(); |
| if (types.some(type => tsutils.isTypeFlagSet(type, ts.TypeFlags.Null | ts.TypeFlags.Undefined | ts.TypeFlags.VoidLike))) { |
| variantTypes.add('nullish'); |
| } |
| const booleans = types.filter(type => tsutils.isTypeFlagSet(type, ts.TypeFlags.BooleanLike)); |
| // If incoming type is either "true" or "false", there will be one type |
| // object with intrinsicName set accordingly |
| // If incoming type is boolean, there will be two type objects with |
| // intrinsicName set "true" and "false" each because of tsutils.unionTypeParts() |
| if (booleans.length === 1) { |
| tsutils.isBooleanLiteralType(booleans[0], true) |
| ? variantTypes.add('truthy boolean') |
| : variantTypes.add('boolean'); |
| } |
| else if (booleans.length === 2) { |
| variantTypes.add('boolean'); |
| } |
| const strings = types.filter(type => tsutils.isTypeFlagSet(type, ts.TypeFlags.StringLike)); |
| if (strings.length) { |
| if (strings.some(type => type.isStringLiteral() && type.value !== '')) { |
| variantTypes.add('truthy string'); |
| } |
| else { |
| variantTypes.add('string'); |
| } |
| } |
| const numbers = types.filter(type => tsutils.isTypeFlagSet(type, ts.TypeFlags.NumberLike | ts.TypeFlags.BigIntLike)); |
| if (numbers.length) { |
| if (numbers.some(type => type.isNumberLiteral() && type.value !== 0)) { |
| variantTypes.add('truthy number'); |
| } |
| else { |
| variantTypes.add('number'); |
| } |
| } |
| if (types.some(type => !tsutils.isTypeFlagSet(type, ts.TypeFlags.Null | |
| ts.TypeFlags.Undefined | |
| ts.TypeFlags.VoidLike | |
| ts.TypeFlags.BooleanLike | |
| ts.TypeFlags.StringLike | |
| ts.TypeFlags.NumberLike | |
| ts.TypeFlags.BigIntLike | |
| ts.TypeFlags.TypeParameter | |
| ts.TypeFlags.Any | |
| ts.TypeFlags.Unknown | |
| ts.TypeFlags.Never))) { |
| variantTypes.add('object'); |
| } |
| if (types.some(type => util.isTypeFlagSet(type, ts.TypeFlags.TypeParameter | |
| ts.TypeFlags.Any | |
| ts.TypeFlags.Unknown))) { |
| variantTypes.add('any'); |
| } |
| if (types.some(type => tsutils.isTypeFlagSet(type, ts.TypeFlags.Never))) { |
| variantTypes.add('never'); |
| } |
| return variantTypes; |
| } |
| }, |
| }); |
| function isLogicalNegationExpression(node) { |
| return node.type === utils_1.AST_NODE_TYPES.UnaryExpression && node.operator === '!'; |
| } |
| function isArrayLengthExpression(node, typeChecker, parserServices) { |
| if (node.type !== utils_1.AST_NODE_TYPES.MemberExpression) { |
| return false; |
| } |
| if (node.computed) { |
| return false; |
| } |
| if (node.property.name !== 'length') { |
| return false; |
| } |
| const objectTsNode = parserServices.esTreeNodeToTSNodeMap.get(node.object); |
| const objectType = util.getConstrainedTypeAtLocation(typeChecker, objectTsNode); |
| return util.isTypeArrayTypeOrUnionOfArrayTypes(objectType, typeChecker); |
| } |
| //# sourceMappingURL=strict-boolean-expressions.js.map |
