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@typescript-eslint/eslint-plugin

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"use strict"; Object.defineProperty(exports, "__esModule", { value: true }); const utils_1 = require("@typescript-eslint/utils"); const util_1 = require("../util"); exports.default = (0, util_1.createRule)({ name: 'consistent-type-imports', meta: { type: 'suggestion', docs: { description: 'Enforce consistent usage of type imports', }, fixable: 'code', messages: { avoidImportType: 'Use an `import` instead of an `import type`.', noImportTypeAnnotations: '`import()` type annotations are forbidden.', someImportsAreOnlyTypes: 'Imports {{typeImports}} are only used as type.', typeOverValue: 'All imports in the declaration are only used as types. Use `import type`.', }, schema: [ { type: 'object', additionalProperties: false, properties: { disallowTypeAnnotations: { type: 'boolean', description: 'Whether to disallow type imports in type annotations (`import()`).', }, fixStyle: { type: 'string', description: 'The expected type modifier to be added when an import is detected as used only in the type position.', enum: ['separate-type-imports', 'inline-type-imports'], }, prefer: { type: 'string', description: 'The expected import kind for type-only imports.', enum: ['type-imports', 'no-type-imports'], }, }, }, ], }, defaultOptions: [ { disallowTypeAnnotations: true, fixStyle: 'separate-type-imports', prefer: 'type-imports', }, ], create(context, [option]) { const prefer = option.prefer ?? 'type-imports'; const disallowTypeAnnotations = option.disallowTypeAnnotations !== false; const selectors = {}; if (disallowTypeAnnotations) { selectors.TSImportType = (node) => { context.report({ node, messageId: 'noImportTypeAnnotations', }); }; } if (prefer === 'no-type-imports') { return { ...selectors, 'ImportDeclaration[importKind = "type"]'(node) { context.report({ node, messageId: 'avoidImportType', fix(fixer) { return fixRemoveTypeSpecifierFromImportDeclaration(fixer, node); }, }); }, 'ImportSpecifier[importKind = "type"]'(node) { context.report({ node, messageId: 'avoidImportType', fix(fixer) { return fixRemoveTypeSpecifierFromImportSpecifier(fixer, node); }, }); }, }; } // prefer type imports const fixStyle = option.fixStyle ?? 'separate-type-imports'; let hasDecoratorMetadata = false; const sourceImportsMap = {}; const emitDecoratorMetadata = (0, util_1.getParserServices)(context, true).emitDecoratorMetadata ?? false; const experimentalDecorators = (0, util_1.getParserServices)(context, true).experimentalDecorators ?? false; if (experimentalDecorators && emitDecoratorMetadata) { selectors.Decorator = () => { hasDecoratorMetadata = true; }; } return { ...selectors, ImportDeclaration(node) { const source = node.source.value; // sourceImports is the object containing all the specifics for a particular import source, type or value sourceImportsMap[source] ??= { reportValueImports: [], // if there is a mismatch where type importKind but value specifiers source, typeOnlyNamedImport: null, // if only type imports valueImport: null, // if only value imports valueOnlyNamedImport: null, // if only value imports with named specifiers }; const sourceImports = sourceImportsMap[source]; if (node.importKind === 'type') { if (!sourceImports.typeOnlyNamedImport && node.specifiers.every(specifier => specifier.type === utils_1.AST_NODE_TYPES.ImportSpecifier)) { // definitely import type { TypeX } sourceImports.typeOnlyNamedImport = node; } } else if (!sourceImports.valueOnlyNamedImport && node.specifiers.length && node.specifiers.every(specifier => specifier.type === utils_1.AST_NODE_TYPES.ImportSpecifier)) { sourceImports.valueOnlyNamedImport = node; sourceImports.valueImport = node; } else if (!sourceImports.valueImport && node.specifiers.some(specifier => specifier.type === utils_1.AST_NODE_TYPES.ImportDefaultSpecifier)) { sourceImports.valueImport = node; } const typeSpecifiers = []; const inlineTypeSpecifiers = []; const valueSpecifiers = []; const unusedSpecifiers = []; for (const specifier of node.specifiers) { if (specifier.type === utils_1.AST_NODE_TYPES.ImportSpecifier && specifier.importKind === 'type') { inlineTypeSpecifiers.push(specifier); continue; } const [variable] = context.sourceCode.getDeclaredVariables(specifier); if (variable.references.length === 0) { unusedSpecifiers.push(specifier); } else { const onlyHasTypeReferences = variable.references.every(ref => { /** * keep origin import kind when export * export { Type } * export default Type; * export = Type; */ if ((ref.identifier.parent.type === utils_1.AST_NODE_TYPES.ExportSpecifier || ref.identifier.parent.type === utils_1.AST_NODE_TYPES.ExportDefaultDeclaration || ref.identifier.parent.type === utils_1.AST_NODE_TYPES.TSExportAssignment) && ref.isValueReference && ref.isTypeReference) { return node.importKind === 'type'; } if (ref.isValueReference) { let parent = ref.identifier.parent; let child = ref.identifier; while (parent) { switch (parent.type) { // CASE 1: // `type T = typeof foo` will create a value reference because "foo" must be a value type // however this value reference is safe to use with type-only imports case utils_1.AST_NODE_TYPES.TSTypeQuery: return true; case utils_1.AST_NODE_TYPES.TSQualifiedName: // TSTypeQuery must have a TSESTree.EntityName as its child, so we can filter here and break early if (parent.left !== child) { return false; } child = parent; parent = parent.parent; continue; // END CASE 1 ////////////// // CASE 2: // `type T = { [foo]: string }` will create a value reference because "foo" must be a value type // however this value reference is safe to use with type-only imports. // Also this is represented as a non-type AST - hence it uses MemberExpression case utils_1.AST_NODE_TYPES.TSPropertySignature: return parent.key === child; case utils_1.AST_NODE_TYPES.MemberExpression: if (parent.object !== child) { return false; } child = parent; parent = parent.parent; continue; // END CASE 2 default: return false; } } } return ref.isTypeReference; }); if (onlyHasTypeReferences) { typeSpecifiers.push(specifier); } else { valueSpecifiers.push(specifier); } } } if (node.importKind === 'value' && typeSpecifiers.length) { sourceImports.reportValueImports.push({ node, inlineTypeSpecifiers, typeSpecifiers, unusedSpecifiers, valueSpecifiers, }); } }, 'Program:exit'() { if (hasDecoratorMetadata) { // Experimental decorator metadata is bowl of poop that cannot be // supported based on pure syntactic analysis. // // So we can do one of two things: // 1) add type-information to the rule in a breaking change and // prevent users from using it so that we can fully support this // case. // 2) make the rule ignore all imports that are used in a file that // might have decorator metadata. // // (1) is has huge impact and prevents the rule from being used by 99% // of users Frankly - it's a straight-up bad option. So instead we // choose with option (2) and just avoid reporting on any imports in a // file with both emitDecoratorMetadata AND decorators // // For more context see the discussion in this issue and its linked // issues: // https://github.com/typescript-eslint/typescript-eslint/issues/5468 // // // NOTE - in TS 5.0 `experimentalDecorators` became the legacy option, // replaced with un-flagged, stable decorators and thus the type-aware // emitDecoratorMetadata implementation also became legacy. in TS 5.2 // support for the new, stable decorator metadata proposal was added - // however this proposal does not include type information // // // PHEW. So TL;DR what does all this mean? // - if you use experimentalDecorators:true, // emitDecoratorMetadata:true, and have a decorator in the file - // the rule will do nothing in the file out of an abundance of // caution. // - else the rule will work as normal. return; } for (const sourceImports of Object.values(sourceImportsMap)) { if (sourceImports.reportValueImports.length === 0) { // nothing to fix. value specifiers and type specifiers are correctly written continue; } for (const report of sourceImports.reportValueImports) { if (report.valueSpecifiers.length === 0 && report.unusedSpecifiers.length === 0 && report.node.importKind !== 'type') { /** * checks if import has type assertions * @example * ```ts * import * as type from 'mod' assert \{ type: 'json' \}; * ``` * https://github.com/typescript-eslint/typescript-eslint/issues/7527 */ if (report.node.attributes.length === 0) { context.report({ node: report.node, messageId: 'typeOverValue', *fix(fixer) { yield* fixToTypeImportDeclaration(fixer, report, sourceImports); }, }); } } else { // we have a mixed type/value import or just value imports, so we need to split them out into multiple imports if separate-type-imports is configured const importNames = report.typeSpecifiers.map(specifier => `"${specifier.local.name}"`); const message = (() => { const typeImports = (0, util_1.formatWordList)(importNames); if (importNames.length === 1) { return { messageId: 'someImportsAreOnlyTypes', data: { typeImports, }, }; } return { messageId: 'someImportsAreOnlyTypes', data: { typeImports, }, }; })(); context.report({ node: report.node, ...message, *fix(fixer) { // take all the typeSpecifiers and put them on a new line yield* fixToTypeImportDeclaration(fixer, report, sourceImports); }, }); } } } }, }; function classifySpecifier(node) { const defaultSpecifier = node.specifiers[0].type === utils_1.AST_NODE_TYPES.ImportDefaultSpecifier ? node.specifiers[0] : null; const namespaceSpecifier = node.specifiers.find((specifier) => specifier.type === utils_1.AST_NODE_TYPES.ImportNamespaceSpecifier) ?? null; const namedSpecifiers = node.specifiers.filter((specifier) => specifier.type === utils_1.AST_NODE_TYPES.ImportSpecifier); return { defaultSpecifier, namedSpecifiers, namespaceSpecifier, }; } /** * Returns information for fixing named specifiers, type or value */ function getFixesNamedSpecifiers(fixer, node, subsetNamedSpecifiers, allNamedSpecifiers) { if (allNamedSpecifiers.length === 0) { return { removeTypeNamedSpecifiers: [], typeNamedSpecifiersText: '', }; } const typeNamedSpecifiersTexts = []; const removeTypeNamedSpecifiers = []; if (subsetNamedSpecifiers.length === allNamedSpecifiers.length) { // import Foo, {Type1, Type2} from 'foo' // import DefType, {Type1, Type2} from 'foo' const openingBraceToken = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(subsetNamedSpecifiers[0], util_1.isOpeningBraceToken), util_1.NullThrowsReasons.MissingToken('{', node.type)); const commaToken = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(openingBraceToken, util_1.isCommaToken), util_1.NullThrowsReasons.MissingToken(',', node.type)); const closingBraceToken = (0, util_1.nullThrows)(context.sourceCode.getFirstTokenBetween(openingBraceToken, node.source, util_1.isClosingBraceToken), util_1.NullThrowsReasons.MissingToken('}', node.type)); // import DefType, {...} from 'foo' // ^^^^^^^ remove removeTypeNamedSpecifiers.push(fixer.removeRange([commaToken.range[0], closingBraceToken.range[1]])); typeNamedSpecifiersTexts.push(context.sourceCode.text.slice(openingBraceToken.range[1], closingBraceToken.range[0])); } else { const namedSpecifierGroups = []; let group = []; for (const namedSpecifier of allNamedSpecifiers) { if (subsetNamedSpecifiers.includes(namedSpecifier)) { group.push(namedSpecifier); } else if (group.length) { namedSpecifierGroups.push(group); group = []; } } if (group.length) { namedSpecifierGroups.push(group); } for (const namedSpecifiers of namedSpecifierGroups) { const { removeRange, textRange } = getNamedSpecifierRanges(namedSpecifiers, allNamedSpecifiers); removeTypeNamedSpecifiers.push(fixer.removeRange(removeRange)); typeNamedSpecifiersTexts.push(context.sourceCode.text.slice(...textRange)); } } return { removeTypeNamedSpecifiers, typeNamedSpecifiersText: typeNamedSpecifiersTexts.join(','), }; } /** * Returns ranges for fixing named specifier. */ function getNamedSpecifierRanges(namedSpecifierGroup, allNamedSpecifiers) { const first = namedSpecifierGroup[0]; const last = namedSpecifierGroup[namedSpecifierGroup.length - 1]; const removeRange = [first.range[0], last.range[1]]; const textRange = [...removeRange]; const before = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(first), util_1.NullThrowsReasons.MissingToken('token', 'first specifier')); textRange[0] = before.range[1]; if ((0, util_1.isCommaToken)(before)) { removeRange[0] = before.range[0]; } else { removeRange[0] = before.range[1]; } const isFirst = allNamedSpecifiers[0] === first; const isLast = allNamedSpecifiers[allNamedSpecifiers.length - 1] === last; const after = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(last), util_1.NullThrowsReasons.MissingToken('token', 'last specifier')); textRange[1] = after.range[0]; if ((isFirst || isLast) && (0, util_1.isCommaToken)(after)) { removeRange[1] = after.range[1]; } return { removeRange, textRange, }; } /** * insert specifiers to named import node. * e.g. * import type { Already, Type1, Type2 } from 'foo' * ^^^^^^^^^^^^^ insert */ function fixInsertNamedSpecifiersInNamedSpecifierList(fixer, target, insertText) { const closingBraceToken = (0, util_1.nullThrows)(context.sourceCode.getFirstTokenBetween((0, util_1.nullThrows)(context.sourceCode.getFirstToken(target), util_1.NullThrowsReasons.MissingToken('token before', 'import')), target.source, util_1.isClosingBraceToken), util_1.NullThrowsReasons.MissingToken('}', target.type)); const before = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(closingBraceToken), util_1.NullThrowsReasons.MissingToken('token before', 'closing brace')); if (!(0, util_1.isCommaToken)(before) && !(0, util_1.isOpeningBraceToken)(before)) { insertText = `,${insertText}`; } return fixer.insertTextBefore(closingBraceToken, insertText); } /** * insert type keyword to named import node. * e.g. * import ADefault, { Already, type Type1, type Type2 } from 'foo' * ^^^^ insert */ function* fixInsertTypeKeywordInNamedSpecifierList(fixer, typeSpecifiers) { for (const spec of typeSpecifiers) { const insertText = context.sourceCode.text.slice(...spec.range); yield fixer.replaceTextRange(spec.range, `type ${insertText}`); } } function* fixInlineTypeImportDeclaration(fixer, report, sourceImports) { const { node } = report; // For a value import, will only add an inline type to named specifiers const { namedSpecifiers } = classifySpecifier(node); const typeNamedSpecifiers = namedSpecifiers.filter(specifier => report.typeSpecifiers.includes(specifier)); if (sourceImports.valueImport) { // add import named type specifiers to its value import // import ValueA, { type A } // ^^^^ insert const { namedSpecifiers: valueImportNamedSpecifiers } = classifySpecifier(sourceImports.valueImport); if (sourceImports.valueOnlyNamedImport || valueImportNamedSpecifiers.length) { yield* fixInsertTypeKeywordInNamedSpecifierList(fixer, typeNamedSpecifiers); } } } function* fixToTypeImportDeclaration(fixer, report, sourceImports) { const { node } = report; const { defaultSpecifier, namedSpecifiers, namespaceSpecifier } = classifySpecifier(node); if (namespaceSpecifier && !defaultSpecifier) { // import * as types from 'foo' // checks for presence of import assertions if (node.attributes.length === 0) { yield* fixInsertTypeSpecifierForImportDeclaration(fixer, node, false); } return; } if (defaultSpecifier) { if (report.typeSpecifiers.includes(defaultSpecifier) && namedSpecifiers.length === 0 && !namespaceSpecifier) { // import Type from 'foo' yield* fixInsertTypeSpecifierForImportDeclaration(fixer, node, true); return; } if (fixStyle === 'inline-type-imports' && !report.typeSpecifiers.includes(defaultSpecifier) && namedSpecifiers.length > 0 && !namespaceSpecifier) { // if there is a default specifier but it isn't a type specifier, then just add the inline type modifier to the named specifiers // import AValue, {BValue, Type1, Type2} from 'foo' yield* fixInlineTypeImportDeclaration(fixer, report, sourceImports); return; } } else if (!namespaceSpecifier) { if (fixStyle === 'inline-type-imports' && namedSpecifiers.some(specifier => report.typeSpecifiers.includes(specifier))) { // import {AValue, Type1, Type2} from 'foo' yield* fixInlineTypeImportDeclaration(fixer, report, sourceImports); return; } if (namedSpecifiers.every(specifier => report.typeSpecifiers.includes(specifier))) { // import {Type1, Type2} from 'foo' yield* fixInsertTypeSpecifierForImportDeclaration(fixer, node, false); return; } } const typeNamedSpecifiers = namedSpecifiers.filter(specifier => report.typeSpecifiers.includes(specifier)); const fixesNamedSpecifiers = getFixesNamedSpecifiers(fixer, node, typeNamedSpecifiers, namedSpecifiers); const afterFixes = []; if (typeNamedSpecifiers.length) { if (sourceImports.typeOnlyNamedImport) { const insertTypeNamedSpecifiers = fixInsertNamedSpecifiersInNamedSpecifierList(fixer, sourceImports.typeOnlyNamedImport, fixesNamedSpecifiers.typeNamedSpecifiersText); if (sourceImports.typeOnlyNamedImport.range[1] <= node.range[0]) { yield insertTypeNamedSpecifiers; } else { afterFixes.push(insertTypeNamedSpecifiers); } } else { // The import is both default and named. Insert named on new line because can't mix default type import and named type imports // eslint-disable-next-line no-lonely-if if (fixStyle === 'inline-type-imports') { yield fixer.insertTextBefore(node, `import {${typeNamedSpecifiers .map(spec => { const insertText = context.sourceCode.text.slice(...spec.range); return `type ${insertText}`; }) .join(', ')}} from ${context.sourceCode.getText(node.source)};\n`); } else { yield fixer.insertTextBefore(node, `import type {${fixesNamedSpecifiers.typeNamedSpecifiersText}} from ${context.sourceCode.getText(node.source)};\n`); } } } const fixesRemoveTypeNamespaceSpecifier = []; if (namespaceSpecifier && report.typeSpecifiers.includes(namespaceSpecifier)) { // import Foo, * as Type from 'foo' // import DefType, * as Type from 'foo' // import DefType, * as Type from 'foo' const commaToken = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(namespaceSpecifier, util_1.isCommaToken), util_1.NullThrowsReasons.MissingToken(',', node.type)); // import Def, * as Ns from 'foo' // ^^^^^^^^^ remove fixesRemoveTypeNamespaceSpecifier.push(fixer.removeRange([commaToken.range[0], namespaceSpecifier.range[1]])); // import type * as Ns from 'foo' // ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ insert yield fixer.insertTextBefore(node, `import type ${context.sourceCode.getText(namespaceSpecifier)} from ${context.sourceCode.getText(node.source)};\n`); } if (defaultSpecifier && report.typeSpecifiers.includes(defaultSpecifier)) { if (report.typeSpecifiers.length === node.specifiers.length) { const importToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isImportKeyword), util_1.NullThrowsReasons.MissingToken('import', node.type)); // import type Type from 'foo' // ^^^^ insert yield fixer.insertTextAfter(importToken, ' type'); } else { const commaToken = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(defaultSpecifier, util_1.isCommaToken), util_1.NullThrowsReasons.MissingToken(',', defaultSpecifier.type)); // import Type , {...} from 'foo' // ^^^^^ pick const defaultText = context.sourceCode.text .slice(defaultSpecifier.range[0], commaToken.range[0]) .trim(); yield fixer.insertTextBefore(node, `import type ${defaultText} from ${context.sourceCode.getText(node.source)};\n`); const afterToken = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(commaToken, { includeComments: true, }), util_1.NullThrowsReasons.MissingToken('any token', node.type)); // import Type , {...} from 'foo' // ^^^^^^^ remove yield fixer.removeRange([ defaultSpecifier.range[0], afterToken.range[0], ]); } } yield* fixesNamedSpecifiers.removeTypeNamedSpecifiers; yield* fixesRemoveTypeNamespaceSpecifier; yield* afterFixes; } function* fixInsertTypeSpecifierForImportDeclaration(fixer, node, isDefaultImport) { // import type Foo from 'foo' // ^^^^^ insert const importToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isImportKeyword), util_1.NullThrowsReasons.MissingToken('import', node.type)); yield fixer.insertTextAfter(importToken, ' type'); if (isDefaultImport) { // Has default import const openingBraceToken = context.sourceCode.getFirstTokenBetween(importToken, node.source, util_1.isOpeningBraceToken); if (openingBraceToken) { // Only braces. e.g. import Foo, {} from 'foo' const commaToken = (0, util_1.nullThrows)(context.sourceCode.getTokenBefore(openingBraceToken, util_1.isCommaToken), util_1.NullThrowsReasons.MissingToken(',', node.type)); const closingBraceToken = (0, util_1.nullThrows)(context.sourceCode.getFirstTokenBetween(openingBraceToken, node.source, util_1.isClosingBraceToken), util_1.NullThrowsReasons.MissingToken('}', node.type)); // import type Foo, {} from 'foo' // ^^ remove yield fixer.removeRange([ commaToken.range[0], closingBraceToken.range[1], ]); const specifiersText = context.sourceCode.text.slice(commaToken.range[1], closingBraceToken.range[1]); if (node.specifiers.length > 1) { yield fixer.insertTextAfter(node, `\nimport type${specifiersText} from ${context.sourceCode.getText(node.source)};`); } } } // make sure we don't do anything like `import type {type T} from 'foo';` for (const specifier of node.specifiers) { if (specifier.type === utils_1.AST_NODE_TYPES.ImportSpecifier && specifier.importKind === 'type') { yield* fixRemoveTypeSpecifierFromImportSpecifier(fixer, specifier); } } } function* fixRemoveTypeSpecifierFromImportDeclaration(fixer, node) { // import type Foo from 'foo' // ^^^^ remove const importToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isImportKeyword), util_1.NullThrowsReasons.MissingToken('import', node.type)); const typeToken = (0, util_1.nullThrows)(context.sourceCode.getFirstTokenBetween(importToken, node.specifiers[0]?.local ?? node.source, util_1.isTypeKeyword), util_1.NullThrowsReasons.MissingToken('type', node.type)); const afterToken = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(typeToken, { includeComments: true }), util_1.NullThrowsReasons.MissingToken('any token', node.type)); yield fixer.removeRange([typeToken.range[0], afterToken.range[0]]); } function* fixRemoveTypeSpecifierFromImportSpecifier(fixer, node) { // import { type Foo } from 'foo' // ^^^^ remove const typeToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node, util_1.isTypeKeyword), util_1.NullThrowsReasons.MissingToken('type', node.type)); const afterToken = (0, util_1.nullThrows)(context.sourceCode.getTokenAfter(typeToken, { includeComments: true }), util_1.NullThrowsReasons.MissingToken('any token', node.type)); yield fixer.removeRange([typeToken.range[0], afterToken.range[0]]); } }, });