| "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 }); |
| exports.phrases = void 0; |
| const experimental_utils_1 = require("@typescript-eslint/experimental-utils"); |
| const util = __importStar(require("../util")); |
| exports.phrases = { |
| [experimental_utils_1.AST_NODE_TYPES.TSTypeLiteral]: 'Type literal', |
| [experimental_utils_1.AST_NODE_TYPES.TSInterfaceDeclaration]: 'Interface', |
| }; |
| exports.default = util.createRule({ |
| name: 'prefer-function-type', |
| meta: { |
| docs: { |
| description: 'Use function types instead of interfaces with call signatures', |
| category: 'Best Practices', |
| recommended: false, |
| }, |
| fixable: 'code', |
| messages: { |
| functionTypeOverCallableType: '{{ literalOrInterface }} only has a call signature, you should use a function type instead.', |
| unexpectedThisOnFunctionOnlyInterface: "`this` refers to the function type '{{ interfaceName }}', did you intend to use a generic `this` parameter like `<Self>(this: Self, ...) => Self` instead?", |
| }, |
| schema: [], |
| type: 'suggestion', |
| }, |
| defaultOptions: [], |
| create(context) { |
| const sourceCode = context.getSourceCode(); |
| /** |
| * Checks if there the interface has exactly one supertype that isn't named 'Function' |
| * @param node The node being checked |
| */ |
| function hasOneSupertype(node) { |
| if (!node.extends || node.extends.length === 0) { |
| return false; |
| } |
| if (node.extends.length !== 1) { |
| return true; |
| } |
| const expr = node.extends[0].expression; |
| return (expr.type !== experimental_utils_1.AST_NODE_TYPES.Identifier || expr.name !== 'Function'); |
| } |
| /** |
| * @param parent The parent of the call signature causing the diagnostic |
| */ |
| function shouldWrapSuggestion(parent) { |
| if (!parent) { |
| return false; |
| } |
| switch (parent.type) { |
| case experimental_utils_1.AST_NODE_TYPES.TSUnionType: |
| case experimental_utils_1.AST_NODE_TYPES.TSIntersectionType: |
| case experimental_utils_1.AST_NODE_TYPES.TSArrayType: |
| return true; |
| default: |
| return false; |
| } |
| } |
| /** |
| * @param call The call signature causing the diagnostic |
| * @param parent The parent of the call |
| * @returns The suggestion to report |
| */ |
| function renderSuggestion(call, parent) { |
| const start = call.range[0]; |
| const colonPos = call.returnType.range[0] - start; |
| const text = sourceCode.getText().slice(start, call.range[1]); |
| let suggestion = `${text.slice(0, colonPos)} =>${text.slice(colonPos + 1)}`; |
| if (shouldWrapSuggestion(parent.parent)) { |
| suggestion = `(${suggestion})`; |
| } |
| if (parent.type === experimental_utils_1.AST_NODE_TYPES.TSInterfaceDeclaration) { |
| if (typeof parent.typeParameters !== 'undefined') { |
| return `type ${sourceCode |
| .getText() |
| .slice(parent.id.range[0], parent.typeParameters.range[1])} = ${suggestion}`; |
| } |
| return `type ${parent.id.name} = ${suggestion}`; |
| } |
| return suggestion.endsWith(';') ? suggestion.slice(0, -1) : suggestion; |
| } |
| /** |
| * @param member The TypeElement being checked |
| * @param node The parent of member being checked |
| */ |
| function checkMember(member, node, tsThisTypes = null) { |
| if ((member.type === experimental_utils_1.AST_NODE_TYPES.TSCallSignatureDeclaration || |
| member.type === experimental_utils_1.AST_NODE_TYPES.TSConstructSignatureDeclaration) && |
| typeof member.returnType !== 'undefined') { |
| if (tsThisTypes !== null && |
| tsThisTypes.length > 0 && |
| node.type === experimental_utils_1.AST_NODE_TYPES.TSInterfaceDeclaration) { |
| // the message can be confusing if we don't point directly to the `this` node instead of the whole member |
| // and in favour of generating at most one error we'll only report the first occurrence of `this` if there are multiple |
| context.report({ |
| node: tsThisTypes[0], |
| messageId: 'unexpectedThisOnFunctionOnlyInterface', |
| data: { |
| interfaceName: node.id.name, |
| }, |
| }); |
| return; |
| } |
| const suggestion = renderSuggestion(member, node); |
| const fixStart = node.type === experimental_utils_1.AST_NODE_TYPES.TSTypeLiteral |
| ? node.range[0] |
| : sourceCode |
| .getTokens(node) |
| .filter(token => token.type === experimental_utils_1.AST_TOKEN_TYPES.Keyword && |
| token.value === 'interface')[0].range[0]; |
| context.report({ |
| node: member, |
| messageId: 'functionTypeOverCallableType', |
| data: { |
| literalOrInterface: exports.phrases[node.type], |
| }, |
| fix(fixer) { |
| return fixer.replaceTextRange([fixStart, node.range[1]], suggestion); |
| }, |
| }); |
| } |
| } |
| let tsThisTypes = null; |
| let literalNesting = 0; |
| return { |
| TSInterfaceDeclaration() { |
| // when entering an interface reset the count of `this`s to empty. |
| tsThisTypes = []; |
| }, |
| 'TSInterfaceDeclaration TSThisType'(node) { |
| // inside an interface keep track of all ThisType references. |
| // unless it's inside a nested type literal in which case it's invalid code anyway |
| // we don't want to incorrectly say "it refers to name" while typescript says it's completely invalid. |
| if (literalNesting === 0 && tsThisTypes !== null) { |
| tsThisTypes.push(node); |
| } |
| }, |
| 'TSInterfaceDeclaration:exit'(node) { |
| if (!hasOneSupertype(node) && node.body.body.length === 1) { |
| checkMember(node.body.body[0], node, tsThisTypes); |
| } |
| // on exit check member and reset the array to nothing. |
| tsThisTypes = null; |
| }, |
| // keep track of nested literals to avoid complaining about invalid `this` uses |
| 'TSInterfaceDeclaration TSTypeLiteral'() { |
| literalNesting += 1; |
| }, |
| 'TSInterfaceDeclaration TSTypeLiteral:exit'() { |
| literalNesting -= 1; |
| }, |
| 'TSTypeLiteral[members.length = 1]'(node) { |
| checkMember(node.members[0], node); |
| }, |
| }; |
| }, |
| }); |
| //# sourceMappingURL=prefer-function-type.js.map |