consistent-type-imports.ts

import type { TSESLint, TSESTree } from '@typescript-eslint/utils';
import { AST_NODE_TYPES } from '@typescript-eslint/utils';
import type { RuleListener } from '@typescript-eslint/utils/eslint-utils';

import {
  createRule,
  formatWordList,
  getParserServices,
  isClosingBraceToken,
  isCommaToken,
  isImportKeyword,
  isOpeningBraceToken,
  isTypeKeyword,
  nullThrows,
  NullThrowsReasons,
} from '../util';

type Prefer = 'no-type-imports' | 'type-imports';
type FixStyle = 'inline-type-imports' | 'separate-type-imports';

type Options = [
  {
    prefer?: Prefer;
    disallowTypeAnnotations?: boolean;
    fixStyle?: FixStyle;
  },
];

interface SourceImports {
  source: string;
  reportValueImports: ReportValueImport[];
  // ImportDeclaration for type-only import only with named imports.
  typeOnlyNamedImport: TSESTree.ImportDeclaration | null;
  // ImportDeclaration for value-only import only with named imports.
  valueOnlyNamedImport: TSESTree.ImportDeclaration | null;
  // ImportDeclaration for value-only import only with default imports and/or named imports.
  valueImport: TSESTree.ImportDeclaration | null;
}
interface ReportValueImport {
  node: TSESTree.ImportDeclaration;
  typeSpecifiers: TSESTree.ImportClause[]; // It has at least one element.
  valueSpecifiers: TSESTree.ImportClause[];
  unusedSpecifiers: TSESTree.ImportClause[];
  inlineTypeSpecifiers: TSESTree.ImportSpecifier[];
}

type MessageIds =
  | 'typeOverValue'
  | 'someImportsAreOnlyTypes'
  | 'avoidImportType'
  | 'noImportTypeAnnotations';
export default createRule<Options, MessageIds>({
  name: 'consistent-type-imports',
  meta: {
    type: 'suggestion',
    docs: {
      description: 'Enforce consistent usage of type imports',
    },
    messages: {
      typeOverValue:
        'All imports in the declaration are only used as types. Use `import type`.',
      someImportsAreOnlyTypes: 'Imports {{typeImports}} are only used as type.',

      avoidImportType: 'Use an `import` instead of an `import type`.',
      noImportTypeAnnotations: '`import()` type annotations are forbidden.',
    },
    schema: [
      {
        type: 'object',
        properties: {
          disallowTypeAnnotations: {
            type: 'boolean',
          },
          fixStyle: {
            type: 'string',
            enum: ['separate-type-imports', 'inline-type-imports'],
          },
          prefer: {
            type: 'string',
            enum: ['type-imports', 'no-type-imports'],
          },
        },
        additionalProperties: false,
      },
    ],
    fixable: 'code',
  },

  defaultOptions: [
    {
      prefer: 'type-imports',
      disallowTypeAnnotations: true,
      fixStyle: 'separate-type-imports',
    },
  ],

  create(context, [option]) {
    const prefer = option.prefer ?? 'type-imports';
    const disallowTypeAnnotations = option.disallowTypeAnnotations !== false;

    const selectors: RuleListener = {};

    if (disallowTypeAnnotations) {
      selectors.TSImportType = (node): void => {
        context.report({
          node,
          messageId: 'noImportTypeAnnotations',
        });
      };
    }

    if (prefer === 'no-type-imports') {
      return {
        ...selectors,
        'ImportDeclaration[importKind = "type"]'(
          node: TSESTree.ImportDeclaration,
        ): void {
          context.report({
            node,
            messageId: 'avoidImportType',
            fix(fixer) {
              return fixRemoveTypeSpecifierFromImportDeclaration(fixer, node);
            },
          });
        },
        'ImportSpecifier[importKind = "type"]'(
          node: TSESTree.ImportSpecifier,
        ): void {
          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: Record<string, SourceImports> = {};

    const emitDecoratorMetadata =
      getParserServices(context, true).emitDecoratorMetadata ?? false;
    const experimentalDecorators =
      getParserServices(context, true).experimentalDecorators ?? false;
    if (experimentalDecorators && emitDecoratorMetadata) {
      selectors.Decorator = (): void => {
        hasDecoratorMetadata = true;
      };
    }

    return {
      ...selectors,

      ImportDeclaration(node): void {
        const source = node.source.value;
        // sourceImports is the object containing all the specifics for a particular import source, type or value
        sourceImportsMap[source] ??= {
          source,
          reportValueImports: [], // if there is a mismatch where type importKind but value specifiers
          typeOnlyNamedImport: null, // if only type imports
          valueOnlyNamedImport: null, // if only value imports with named specifiers
          valueImport: null, // if only value imports
        };
        const sourceImports = sourceImportsMap[source];
        if (node.importKind === 'type') {
          if (
            !sourceImports.typeOnlyNamedImport &&
            node.specifiers.every(
              specifier => specifier.type === AST_NODE_TYPES.ImportSpecifier,
            )
          ) {
            // definitely import type { TypeX }
            sourceImports.typeOnlyNamedImport = node;
          }
        } else {
          if (
            !sourceImports.valueOnlyNamedImport &&
            node.specifiers.length &&
            node.specifiers.every(
              specifier => specifier.type === AST_NODE_TYPES.ImportSpecifier,
            )
          ) {
            sourceImports.valueOnlyNamedImport = node;
            sourceImports.valueImport = node;
          } else if (
            !sourceImports.valueImport &&
            node.specifiers.some(
              specifier =>
                specifier.type === AST_NODE_TYPES.ImportDefaultSpecifier,
            )
          ) {
            sourceImports.valueImport = node;
          }
        }

        const typeSpecifiers: TSESTree.ImportClause[] = [];
        const inlineTypeSpecifiers: TSESTree.ImportSpecifier[] = [];
        const valueSpecifiers: TSESTree.ImportClause[] = [];
        const unusedSpecifiers: TSESTree.ImportClause[] = [];
        for (const specifier of node.specifiers) {
          if (
            specifier.type === 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 === AST_NODE_TYPES.ExportSpecifier ||
                ref.identifier.parent.type ===
                  AST_NODE_TYPES.ExportDefaultDeclaration ||
                ref.identifier.parent.type === AST_NODE_TYPES.TSExportAssignment
              ) {
                if (ref.isValueReference && ref.isTypeReference) {
                  return node.importKind === 'type';
                }
              }
              if (ref.isValueReference) {
                let parent = ref.identifier.parent as TSESTree.Node | undefined;
                let child: TSESTree.Node = 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 AST_NODE_TYPES.TSTypeQuery:
                      return true;

                    case 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 AST_NODE_TYPES.TSPropertySignature:
                      return parent.key === child;

                    case 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,
            typeSpecifiers,
            valueSpecifiers,
            unusedSpecifiers,
            inlineTypeSpecifiers,
          });
        }
      },

      'Program:exit'(): void {
        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
               * ```
               * 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 = ((): {
                messageId: MessageIds;
                data: Record<string, unknown>;
              } => {
                const typeImports = 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: TSESTree.ImportDeclaration): {
      defaultSpecifier: TSESTree.ImportDefaultSpecifier | null;
      namespaceSpecifier: TSESTree.ImportNamespaceSpecifier | null;
      namedSpecifiers: TSESTree.ImportSpecifier[];
    } {
      const defaultSpecifier =
        node.specifiers[0].type === AST_NODE_TYPES.ImportDefaultSpecifier
          ? node.specifiers[0]
          : null;
      const namespaceSpecifier =
        node.specifiers.find(
          (specifier): specifier is TSESTree.ImportNamespaceSpecifier =>
            specifier.type === AST_NODE_TYPES.ImportNamespaceSpecifier,
        ) ?? null;
      const namedSpecifiers = node.specifiers.filter(
        (specifier): specifier is TSESTree.ImportSpecifier =>
          specifier.type === AST_NODE_TYPES.ImportSpecifier,
      );
      return {
        defaultSpecifier,
        namespaceSpecifier,
        namedSpecifiers,
      };
    }

    /**
     * Returns information for fixing named specifiers, type or value
     */
    function getFixesNamedSpecifiers(
      fixer: TSESLint.RuleFixer,
      node: TSESTree.ImportDeclaration,
      subsetNamedSpecifiers: TSESTree.ImportSpecifier[],
      allNamedSpecifiers: TSESTree.ImportSpecifier[],
    ): {
      typeNamedSpecifiersText: string;
      removeTypeNamedSpecifiers: TSESLint.RuleFix[];
    } {
      if (allNamedSpecifiers.length === 0) {
        return {
          typeNamedSpecifiersText: '',
          removeTypeNamedSpecifiers: [],
        };
      }
      const typeNamedSpecifiersTexts: string[] = [];
      const removeTypeNamedSpecifiers: TSESLint.RuleFix[] = [];
      if (subsetNamedSpecifiers.length === allNamedSpecifiers.length) {
        // import Foo, {Type1, Type2} from 'foo'
        // import DefType, {Type1, Type2} from 'foo'
        const openingBraceToken = nullThrows(
          context.sourceCode.getTokenBefore(
            subsetNamedSpecifiers[0],
            isOpeningBraceToken,
          ),
          NullThrowsReasons.MissingToken('{', node.type),
        );
        const commaToken = nullThrows(
          context.sourceCode.getTokenBefore(openingBraceToken, isCommaToken),
          NullThrowsReasons.MissingToken(',', node.type),
        );
        const closingBraceToken = nullThrows(
          context.sourceCode.getFirstTokenBetween(
            openingBraceToken,
            node.source,
            isClosingBraceToken,
          ),
          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: TSESTree.ImportSpecifier[][] = [];
        let group: TSESTree.ImportSpecifier[] = [];
        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 {
        typeNamedSpecifiersText: typeNamedSpecifiersTexts.join(','),
        removeTypeNamedSpecifiers,
      };
    }

    /**
     * Returns ranges for fixing named specifier.
     */
    function getNamedSpecifierRanges(
      namedSpecifierGroup: TSESTree.ImportSpecifier[],
      allNamedSpecifiers: TSESTree.ImportSpecifier[],
    ): {
      textRange: TSESTree.Range;
      removeRange: TSESTree.Range;
    } {
      const first = namedSpecifierGroup[0];
      const last = namedSpecifierGroup[namedSpecifierGroup.length - 1];
      const removeRange: TSESTree.Range = [first.range[0], last.range[1]];
      const textRange: TSESTree.Range = [...removeRange];
      const before = nullThrows(
        context.sourceCode.getTokenBefore(first),
        NullThrowsReasons.MissingToken('token', 'first specifier'),
      );
      textRange[0] = before.range[1];
      if (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 = nullThrows(
        context.sourceCode.getTokenAfter(last),
        NullThrowsReasons.MissingToken('token', 'last specifier'),
      );
      textRange[1] = after.range[0];
      if (isFirst || isLast) {
        if (isCommaToken(after)) {
          removeRange[1] = after.range[1];
        }
      }

      return {
        textRange,
        removeRange,
      };
    }

    /**
     * insert specifiers to named import node.
     * e.g.
     * import type { Already, Type1, Type2 } from 'foo'
     *                        ^^^^^^^^^^^^^ insert
     */
    function fixInsertNamedSpecifiersInNamedSpecifierList(
      fixer: TSESLint.RuleFixer,
      target: TSESTree.ImportDeclaration,
      insertText: string,
    ): TSESLint.RuleFix {
      const closingBraceToken = nullThrows(
        context.sourceCode.getFirstTokenBetween(
          nullThrows(
            context.sourceCode.getFirstToken(target),
            NullThrowsReasons.MissingToken('token before', 'import'),
          ),
          target.source,
          isClosingBraceToken,
        ),
        NullThrowsReasons.MissingToken('}', target.type),
      );
      const before = nullThrows(
        context.sourceCode.getTokenBefore(closingBraceToken),
        NullThrowsReasons.MissingToken('token before', 'closing brace'),
      );
      if (!isCommaToken(before) && !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: TSESLint.RuleFixer,
      typeSpecifiers: TSESTree.ImportSpecifier[],
    ): IterableIterator<TSESLint.RuleFix> {
      for (const spec of typeSpecifiers) {
        const insertText = context.sourceCode.text.slice(...spec.range);
        yield fixer.replaceTextRange(spec.range, `type ${insertText}`);
      }
    }

    function* fixInlineTypeImportDeclaration(
      fixer: TSESLint.RuleFixer,
      report: ReportValueImport,
      sourceImports: SourceImports,
    ): IterableIterator<TSESLint.RuleFix> {
      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: TSESLint.RuleFixer,
      report: ReportValueImport,
      sourceImports: SourceImports,
    ): IterableIterator<TSESLint.RuleFix> {
      const { node } = report;

      const { defaultSpecifier, namespaceSpecifier, namedSpecifiers } =
        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;
      } else if (defaultSpecifier) {
        if (
          report.typeSpecifiers.includes(defaultSpecifier) &&
          namedSpecifiers.length === 0 &&
          !namespaceSpecifier
        ) {
          // import Type from 'foo'
          yield* fixInsertTypeSpecifierForImportDeclaration(fixer, node, true);
          return;
        } else 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;
        } else 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: TSESLint.RuleFix[] = [];
      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
          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: TSESLint.RuleFix[] = [];
      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 = nullThrows(
          context.sourceCode.getTokenBefore(namespaceSpecifier, isCommaToken),
          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 = nullThrows(
            context.sourceCode.getFirstToken(node, isImportKeyword),
            NullThrowsReasons.MissingToken('import', node.type),
          );
          // import type Type from 'foo'
          //        ^^^^ insert
          yield fixer.insertTextAfter(importToken, ' type');
        } else {
          const commaToken = nullThrows(
            context.sourceCode.getTokenAfter(defaultSpecifier, isCommaToken),
            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 = nullThrows(
            context.sourceCode.getTokenAfter(commaToken, {
              includeComments: true,
            }),
            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: TSESLint.RuleFixer,
      node: TSESTree.ImportDeclaration,
      isDefaultImport: boolean,
    ): IterableIterator<TSESLint.RuleFix> {
      // import type Foo from 'foo'
      //       ^^^^^ insert
      const importToken = nullThrows(
        context.sourceCode.getFirstToken(node, isImportKeyword),
        NullThrowsReasons.MissingToken('import', node.type),
      );
      yield fixer.insertTextAfter(importToken, ' type');

      if (isDefaultImport) {
        // Has default import
        const openingBraceToken = context.sourceCode.getFirstTokenBetween(
          importToken,
          node.source,
          isOpeningBraceToken,
        );
        if (openingBraceToken) {
          // Only braces. e.g. import Foo, {} from 'foo'
          const commaToken = nullThrows(
            context.sourceCode.getTokenBefore(openingBraceToken, isCommaToken),
            NullThrowsReasons.MissingToken(',', node.type),
          );
          const closingBraceToken = nullThrows(
            context.sourceCode.getFirstTokenBetween(
              openingBraceToken,
              node.source,
              isClosingBraceToken,
            ),
            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 === AST_NODE_TYPES.ImportSpecifier &&
          specifier.importKind === 'type'
        ) {
          yield* fixRemoveTypeSpecifierFromImportSpecifier(fixer, specifier);
        }
      }
    }

    function* fixRemoveTypeSpecifierFromImportDeclaration(
      fixer: TSESLint.RuleFixer,
      node: TSESTree.ImportDeclaration,
    ): IterableIterator<TSESLint.RuleFix> {
      // import type Foo from 'foo'
      //        ^^^^ remove
      const importToken = nullThrows(
        context.sourceCode.getFirstToken(node, isImportKeyword),
        NullThrowsReasons.MissingToken('import', node.type),
      );
      const typeToken = nullThrows(
        context.sourceCode.getFirstTokenBetween(
          importToken,
          node.specifiers[0]?.local ?? node.source,
          isTypeKeyword,
        ),
        NullThrowsReasons.MissingToken('type', node.type),
      );
      const afterToken = nullThrows(
        context.sourceCode.getTokenAfter(typeToken, { includeComments: true }),
        NullThrowsReasons.MissingToken('any token', node.type),
      );
      yield fixer.removeRange([typeToken.range[0], afterToken.range[0]]);
    }

    function* fixRemoveTypeSpecifierFromImportSpecifier(
      fixer: TSESLint.RuleFixer,
      node: TSESTree.ImportSpecifier,
    ): IterableIterator<TSESLint.RuleFix> {
      // import { type Foo } from 'foo'
      //          ^^^^ remove
      const typeToken = nullThrows(
        context.sourceCode.getFirstToken(node, isTypeKeyword),
        NullThrowsReasons.MissingToken('type', node.type),
      );
      const afterToken = nullThrows(
        context.sourceCode.getTokenAfter(typeToken, { includeComments: true }),
        NullThrowsReasons.MissingToken('any token', node.type),
      );
      yield fixer.removeRange([typeToken.range[0], afterToken.range[0]]);
    }
  },
});