linter.test.ts

import * as path from 'path';
import {
  checkFilesExist,
  cleanupProject,
  createFile,
  newProject,
  readFile,
  readJson,
  runCLI,
  uniq,
  updateFile,
} from '@nrwl/e2e/utils';
import * as ts from 'typescript';

/**
 * Importing this helper from @typescript-eslint/type-utils to ensure
 * compatibility with TS < 4.8 due to the API change in TS4.8.
 * This helper allows for support of TS <= 4.8.
 */
import { getDecorators, getModifiers } from '@typescript-eslint/type-utils';

describe('Linter', () => {
  describe('linting errors', () => {
    afterEach(() => cleanupProject());

    it('should handle linting errors', () => {
      const myapp = uniq('myapp');

      newProject();
      runCLI(`generate @nrwl/react:app ${myapp}`);
      // create faulty file
      updateFile(`apps/${myapp}/src/main.ts`, `console.log("should fail");`);
      const eslintrc = readJson('.eslintrc.json');

      // set the eslint rules to error
      eslintrc.overrides.forEach((override) => {
        if (override.files.includes('*.ts')) {
          override.rules['no-console'] = 'error';
        }
      });
      updateFile('.eslintrc.json', JSON.stringify(eslintrc, null, 2));

      // 1. linting should error when rules are not followed
      let out = runCLI(`lint ${myapp}`, { silenceError: true });
      expect(out).toContain('Unexpected console statement');

      // 2. linting should not error when rules are not followed and the force flag is specified
      expect(() => runCLI(`lint ${myapp} --force`)).not.toThrow();

      eslintrc.overrides.forEach((override) => {
        if (override.files.includes('*.ts')) {
          override.rules['no-console'] = undefined;
        }
      });
      updateFile('.eslintrc.json', JSON.stringify(eslintrc, null, 2));

      // 3. linting should not error when all rules are followed
      out = runCLI(`lint ${myapp}`, { silenceError: true });
      expect(out).toContain('All files pass linting');
    }, 1000000);

    it('should cache eslint with --cache', () => {
      function readCacheFile(cacheFile) {
        const cacheInfo = readFile(cacheFile);
        return process.platform === 'win32'
          ? cacheInfo.replace(/\\\\/g, '\\')
          : cacheInfo;
      }
      const myapp = uniq('myapp');

      newProject();
      runCLI(`generate @nrwl/react:app ${myapp}`);

      // should generate a default cache file
      expect(() => checkFilesExist(`.eslintcache`)).toThrow();
      runCLI(`lint ${myapp} --cache`, { silenceError: true });
      expect(() => checkFilesExist(`.eslintcache`)).not.toThrow();
      expect(readCacheFile(`.eslintcache`)).toContain(
        path.normalize(`${myapp}/src/app/app.spec.tsx`)
      );

      // should let you specify a cache file location
      expect(() => checkFilesExist(`my-cache`)).toThrow();
      runCLI(`lint ${myapp} --cache --cache-location="my-cache"`, {
        silenceError: true,
      });
      expect(() => checkFilesExist(`my-cache/${myapp}`)).not.toThrow();
      expect(readCacheFile(`my-cache/${myapp}`)).toContain(
        path.normalize(`${myapp}/src/app/app.spec.tsx`)
      );
    });

    it('linting should generate an output file with a specific format', () => {
      newProject();
      const myapp = uniq('myapp');
      runCLI(`generate @nrwl/react:app ${myapp}`);

      const eslintrc = readJson('.eslintrc.json');
      eslintrc.overrides.forEach((override) => {
        if (override.files.includes('*.ts')) {
          override.rules['no-console'] = 'error';
        }
      });
      updateFile('.eslintrc.json', JSON.stringify(eslintrc, null, 2));
      updateFile(`apps/${myapp}/src/main.ts`, `console.log("should fail");`);

      const outputFile = 'a/b/c/lint-output.json';
      expect(() => {
        checkFilesExist(outputFile);
      }).toThrow();
      const stdout = runCLI(
        `lint ${myapp} --output-file="${outputFile}" --format=json`,
        {
          silenceError: true,
        }
      );
      expect(stdout).not.toContain('Unexpected console statement');
      expect(() => checkFilesExist(outputFile)).not.toThrow();
      const outputContents = JSON.parse(readFile(outputFile));
      const outputForApp: any = Object.values(outputContents).filter(
        (result: any) =>
          result.filePath.includes(path.normalize(`${myapp}/src/main.ts`))
      )[0];
      expect(outputForApp.errorCount).toBe(1);
      expect(outputForApp.messages[0].ruleId).toBe('no-console');
      expect(outputForApp.messages[0].message).toBe(
        'Unexpected console statement.'
      );
    }, 1000000);

    it('should support creating, testing and using workspace lint rules', () => {
      const myapp = uniq('myapp');
      const mylib = uniq('mylib');

      const messageId = 'e2eMessageId';
      const libMethodName = 'getMessageId';

      const projScope = newProject();
      runCLI(`generate @nrwl/react:app ${myapp}`);
      runCLI(`generate @nrwl/workspace:lib ${mylib}`);
      // add custom function
      updateFile(
        `libs/${mylib}/src/lib/${mylib}.ts`,
        `export const ${libMethodName} = (): '${messageId}' => '${messageId}';`
      );

      // Generate a new rule (should also scaffold the required workspace project and tests)
      const newRuleName = 'e2e-test-rule-name';
      runCLI(`generate @nrwl/linter:workspace-rule ${newRuleName}`);

      // Ensure that the unit tests for the new rule are runnable
      const unitTestsOutput = runCLI(`test eslint-rules`);
      expect(unitTestsOutput).toContain('Successfully ran target test');

      // Update the rule for the e2e test so that we can assert that it produces the expected lint failure when used
      const knownLintErrorMessage = 'e2e test known error message';
      const newRulePath = `tools/eslint-rules/rules/${newRuleName}.ts`;
      const newRuleGeneratedContents = readFile(newRulePath);
      const updatedRuleContents = updateGeneratedRuleImplementation(
        newRulePath,
        newRuleGeneratedContents,
        knownLintErrorMessage,
        messageId,
        libMethodName,
        `@${projScope}/${mylib}`
      );
      updateFile(newRulePath, updatedRuleContents);

      const newRuleNameForUsage = `@nrwl/nx/workspace/${newRuleName}`;

      // Add the new workspace rule to the lint config and run linting
      const eslintrc = readJson('.eslintrc.json');
      eslintrc.overrides.forEach((override) => {
        if (override.files.includes('*.ts')) {
          override.rules[newRuleNameForUsage] = 'error';
        }
      });
      updateFile('.eslintrc.json', JSON.stringify(eslintrc, null, 2));

      const lintOutput = runCLI(`lint ${myapp} --verbose`, {
        silenceError: true,
      });
      expect(lintOutput).toContain(newRuleNameForUsage);
      expect(lintOutput).toContain(knownLintErrorMessage);
    }, 1000000);

    it('lint plugin should ensure module boundaries', () => {
      const proj = newProject();
      const myapp = uniq('myapp');
      const myapp2 = uniq('myapp2');
      const mylib = uniq('mylib');
      const lazylib = uniq('lazylib');
      const invalidtaglib = uniq('invalidtaglib');
      const validtaglib = uniq('validtaglib');

      runCLI(`generate @nrwl/angular:app ${myapp} --tags=validtag`);
      runCLI(`generate @nrwl/angular:app ${myapp2}`);
      runCLI(`generate @nrwl/angular:lib ${mylib}`);
      runCLI(`generate @nrwl/angular:lib ${lazylib}`);
      runCLI(`generate @nrwl/angular:lib ${invalidtaglib} --tags=invalidtag`);
      runCLI(`generate @nrwl/angular:lib ${validtaglib} --tags=validtag`);

      const eslint = readJson('.eslintrc.json');
      eslint.overrides[0].rules[
        '@nrwl/nx/enforce-module-boundaries'
      ][1].depConstraints = [
        { sourceTag: 'validtag', onlyDependOnLibsWithTags: ['validtag'] },
        ...eslint.overrides[0].rules['@nrwl/nx/enforce-module-boundaries'][1]
          .depConstraints,
      ];
      updateFile('.eslintrc.json', JSON.stringify(eslint, null, 2));

      const tsConfig = readJson('tsconfig.base.json');

      /**
       * apps do not add themselves to the tsconfig file.
       *
       * Let's add it so that we can trigger the lint failure
       */
      tsConfig.compilerOptions.paths[`@${proj}/${myapp2}`] = [
        `apps/${myapp2}/src/main.ts`,
      ];

      tsConfig.compilerOptions.paths[`@secondScope/${lazylib}`] =
        tsConfig.compilerOptions.paths[`@${proj}/${lazylib}`];
      delete tsConfig.compilerOptions.paths[`@${proj}/${lazylib}`];
      updateFile('tsconfig.base.json', JSON.stringify(tsConfig, null, 2));

      updateFile(
        `apps/${myapp}/src/main.ts`,
        `
      import '../../../libs/${mylib}';
      import '@secondScope/${lazylib}';
      import '@${proj}/${myapp2}';
      import '@${proj}/${invalidtaglib}';
      import '@${proj}/${validtaglib}';

      const s = {loadChildren: '@${proj}/${lazylib}'};
    `
      );

      const out = runCLI(`lint ${myapp}`, { silenceError: true });
      expect(out).toContain(
        'Projects cannot be imported by a relative or absolute path, and must begin with a npm scope'
      );
      expect(out).toContain('Imports of apps are forbidden');
      expect(out).toContain(
        'A project tagged with "validtag" can only depend on libs tagged with "validtag"'
      );
    }, 1000000);
  });

  describe('workspace boundary rules', () => {
    const libA = uniq('tslib-a');
    const libB = uniq('tslib-b');
    const libC = uniq('tslib-c');
    let projScope;

    beforeAll(() => {
      projScope = newProject();
      runCLI(`generate @nrwl/workspace:lib ${libA}`);
      runCLI(`generate @nrwl/workspace:lib ${libB}`);
      runCLI(`generate @nrwl/workspace:lib ${libC}`);

      /**
       * create tslib-a structure
       */
      createFile(
        `libs/${libA}/src/lib/tslib-a.ts`,
        `
      export function libASayHi(): string {
        return 'hi there';
      }

      export function libASayHello(): string {
        return 'Hi from tslib-a';
      }
      `
      );

      createFile(
        `libs/${libA}/src/lib/some-non-exported-function.ts`,
        `
      export function someNonPublicLibFunction() {
        return 'this function is exported, but not via the libs barrel file';
      }

      export function someSelectivelyExportedFn() {
        return 'this fn is exported selectively in the barrel file';
      }
      `
      );

      createFile(
        `libs/${libA}/src/index.ts`,
        `
      export * from './lib/tslib-a';

      export { someSelectivelyExportedFn } from './lib/some-non-exported-function';
      `
      );

      /**
       * create tslib-b structure
       */
      createFile(
        `libs/${libB}/src/index.ts`,
        `
      export * from './lib/tslib-b';
      `
      );

      createFile(
        `libs/${libB}/src/lib/tslib-b.ts`,
        `
        import { libASayHi } from 'libs/${libA}/src/lib/tslib-a';
        import { libASayHello } from '../../../${libA}/src/lib/tslib-a';
        // import { someNonPublicLibFunction } from '../../../${libA}/src/lib/some-non-exported-function';
        import { someSelectivelyExportedFn } from '../../../${libA}/src/lib/some-non-exported-function';

        export function tslibB(): string {
          // someNonPublicLibFunction();
          someSelectivelyExportedFn();
          libASayHi();
          libASayHello();
          return 'hi there';
        }
      `
      );

      /**
       * create tslib-c structure
       */

      createFile(
        `libs/${libC}/src/index.ts`,
        `
      export * from './lib/tslib-c';
      export * from './lib/constant';

      `
      );

      createFile(
        `libs/${libC}/src/lib/constant.ts`,
        `
      export const SOME_CONSTANT = 'some constant value';
      export const someFunc1 = () => 'hi';
      export function someFunc2() {
        return 'hi2';
      }
      `
      );

      createFile(
        `libs/${libC}/src/lib/tslib-c-another.ts`,
        `
import { tslibC, SOME_CONSTANT, someFunc1, someFunc2 } from '@${projScope}/${libC}';

export function someStuff() {
  someFunc1();
  someFunc2();
  tslibC();
  console.log(SOME_CONSTANT);
  return 'hi';
}

      `
      );

      createFile(
        `libs/${libC}/src/lib/tslib-c.ts`,
        `
import { someFunc1, someFunc2, SOME_CONSTANT } from '@${projScope}/${libC}';

export function tslibC(): string {
  someFunc1();
  someFunc2();
  console.log(SOME_CONSTANT);
  return 'tslib-c';
}

      `
      );
    });

    afterAll(() => cleanupProject());

    it('should fix noSelfCircularDependencies', () => {
      const stdout = runCLI(`lint ${libC}`, {
        silenceError: true,
      });
      expect(stdout).toContain(
        'Projects should use relative imports to import from other files within the same project'
      );

      // fix them
      const fixedStout = runCLI(`lint ${libC} --fix`, {
        silenceError: true,
      });
      expect(fixedStout).toContain('Successfully ran target lint for project');

      const fileContent = readFile(`libs/${libC}/src/lib/tslib-c-another.ts`);
      expect(fileContent).toContain(`import { tslibC } from './tslib-c';`);
      expect(fileContent).toContain(
        `import { SOME_CONSTANT, someFunc1, someFunc2 } from './constant';`
      );

      const fileContentTslibC = readFile(`libs/${libC}/src/lib/tslib-c.ts`);
      expect(fileContentTslibC).toContain(
        `import { someFunc1, someFunc2, SOME_CONSTANT } from './constant';`
      );
    });

    it('should fix noRelativeOrAbsoluteImportsAcrossLibraries', () => {
      const stdout = runCLI(`lint ${libB}`, {
        silenceError: true,
      });
      expect(stdout).toContain(
        'Projects cannot be imported by a relative or absolute path, and must begin with a npm scope'
      );

      // fix them
      const fixedStout = runCLI(`lint ${libB} --fix`, {
        silenceError: true,
      });
      expect(fixedStout).toContain('Successfully ran target lint for project');

      const fileContent = readFile(`libs/${libB}/src/lib/tslib-b.ts`);
      expect(fileContent).toContain(
        `import { libASayHello } from '@${projScope}/${libA}';`
      );
      expect(fileContent).toContain(
        `import { libASayHi } from '@${projScope}/${libA}';`
      );
      expect(fileContent).toContain(
        `import { someSelectivelyExportedFn } from '@${projScope}/${libA}';`
      );
    });
  });

  describe('Root projects migration', () => {
    afterEach(() => cleanupProject());

    it('(React standalone) should set root project config to app and e2e app and migrate when another lib is added', () => {
      const myapp = uniq('myapp');
      const mylib = uniq('mylib');

      newProject();
      runCLI(`generate @nrwl/react:app ${myapp} --rootProject=true`);

      let rootEslint = readJson('.eslintrc.json');
      let e2eEslint = readJson('e2e/.eslintrc.json');
      expect(() => checkFilesExist(`.eslintrc.base.json`)).toThrow();

      // should directly refer to nx plugin
      expect(rootEslint.plugins).toEqual(['@nrwl/nx']);
      expect(e2eEslint.plugins).toEqual(['@nrwl/nx']);
      // should only extend framework plugin
      expect(rootEslint.extends).toEqual(['plugin:@nrwl/nx/react']);
      expect(e2eEslint.extends).toEqual(['plugin:cypress/recommended']);
      // should have plugin extends
      expect(rootEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/typescript',
      ]);
      expect(rootEslint.overrides[1].extends).toEqual([
        'plugin:@nrwl/nx/javascript',
      ]);
      expect(e2eEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/typescript',
      ]);
      expect(e2eEslint.overrides[1].extends).toEqual([
        'plugin:@nrwl/nx/javascript',
      ]);

      runCLI(`generate @nrwl/react:lib ${mylib}`);
      // should add new tslint
      expect(() => checkFilesExist(`.eslintrc.base.json`)).not.toThrow();
      const appEslint = readJson(`.eslintrc.json`);
      rootEslint = readJson('.eslintrc.base.json');
      e2eEslint = readJson('e2e/.eslintrc.json');
      const libEslint = readJson(`libs/${mylib}/.eslintrc.json`);

      // should directly refer to nx plugin only in the root
      expect(rootEslint.plugins).toEqual(['@nrwl/nx']);
      expect(appEslint.plugins).toBeUndefined();
      expect(e2eEslint.plugins).toBeUndefined();
      // should extend framework plugin and root config
      expect(appEslint.extends).toEqual([
        'plugin:@nrwl/nx/react',
        './.eslintrc.base.json',
      ]);
      expect(e2eEslint.extends).toEqual([
        'plugin:cypress/recommended',
        '../.eslintrc.base.json',
      ]);
      expect(libEslint.extends).toEqual([
        'plugin:@nrwl/nx/react',
        '../../.eslintrc.base.json',
      ]);
      // should have no plugin extends
      expect(appEslint.overrides[0].extends).toBeUndefined();
      expect(appEslint.overrides[1].extends).toBeUndefined();
      expect(e2eEslint.overrides[0].extends).toBeUndefined();
      expect(e2eEslint.overrides[1].extends).toBeUndefined();
      expect(libEslint.overrides[1].extends).toBeUndefined();
      expect(libEslint.overrides[1].extends).toBeUndefined();
    });

    it('(Angular standalone) should set root project config to app and e2e app and migrate when another lib is added', () => {
      const myapp = uniq('myapp');
      const mylib = uniq('mylib');

      newProject();
      runCLI(`generate @nrwl/angular:app ${myapp} --rootProject=true`);

      let rootEslint = readJson('.eslintrc.json');
      let e2eEslint = readJson('e2e/.eslintrc.json');
      expect(() => checkFilesExist(`.eslintrc.base.json`)).toThrow();

      // should directly refer to nx plugin
      expect(rootEslint.plugins).toEqual(['@nrwl/nx']);
      expect(e2eEslint.plugins).toEqual(['@nrwl/nx']);
      // should only extend framework plugin
      expect(e2eEslint.extends).toEqual(['plugin:cypress/recommended']);
      // should have plugin extends
      expect(rootEslint.overrides[0].files).toEqual(['*.ts']);
      expect(rootEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/typescript',
        'plugin:@nrwl/nx/angular',
        'plugin:@angular-eslint/template/process-inline-templates',
      ]);
      expect(Object.keys(rootEslint.overrides[0].rules)).toEqual([
        '@angular-eslint/directive-selector',
        '@angular-eslint/component-selector',
      ]);
      expect(rootEslint.overrides[1].files).toEqual(['*.html']);
      expect(rootEslint.overrides[1].extends).toEqual([
        'plugin:@nrwl/nx/angular-template',
      ]);
      expect(e2eEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/typescript',
      ]);
      expect(e2eEslint.overrides[1].extends).toEqual([
        'plugin:@nrwl/nx/javascript',
      ]);

      runCLI(`generate @nrwl/angular:lib ${mylib}`);
      // should add new tslint
      expect(() => checkFilesExist(`.eslintrc.base.json`)).not.toThrow();
      const appEslint = readJson(`.eslintrc.json`);
      rootEslint = readJson('.eslintrc.base.json');
      e2eEslint = readJson('e2e/.eslintrc.json');
      const libEslint = readJson(`libs/${mylib}/.eslintrc.json`);

      // should directly refer to nx plugin only in the root
      expect(rootEslint.plugins).toEqual(['@nrwl/nx']);
      expect(appEslint.plugins).toBeUndefined();
      expect(e2eEslint.plugins).toBeUndefined();
      // should extend framework plugin and root config
      expect(appEslint.extends).toEqual(['./.eslintrc.base.json']);
      expect(e2eEslint.extends).toEqual([
        'plugin:cypress/recommended',
        '../.eslintrc.base.json',
      ]);
      expect(libEslint.extends).toEqual(['../../.eslintrc.base.json']);
      // should have no plugin extends
      expect(appEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/angular',
        'plugin:@angular-eslint/template/process-inline-templates',
      ]);
      expect(e2eEslint.overrides[0].extends).toBeUndefined();
      expect(e2eEslint.overrides[1].extends).toBeUndefined();
      expect(libEslint.overrides[0].extends).toEqual([
        'plugin:@nrwl/nx/angular',
        'plugin:@angular-eslint/template/process-inline-templates',
      ]);
    });
  });
});

/**
 * Update the generated rule implementation to produce a known lint error from all files.
 *
 * It is important that we do this surgically via AST transformations, otherwise we will
 * drift further and further away from the original generated code and therefore make our
 * e2e test less accurate and less valuable.
 */
function updateGeneratedRuleImplementation(
  newRulePath: string,
  newRuleGeneratedContents: string,
  knownLintErrorMessage: string,
  messageId,
  libMethodName: string,
  libPath: string
): string {
  const printer = ts.createPrinter({ newLine: ts.NewLineKind.LineFeed });
  const newRuleSourceFile = ts.createSourceFile(
    newRulePath,
    newRuleGeneratedContents,
    ts.ScriptTarget.Latest,
    true
  );

  const transformer =
    <T extends ts.SourceFile>(context: ts.TransformationContext) =>
    (rootNode: T) => {
      function visit(node: ts.Node): ts.Node {
        /**
         * Add an ESLint messageId which will show the knownLintErrorMessage
         *
         * i.e.
         *
         * messages: {
         *   e2eMessageId: knownLintErrorMessage
         * }
         */
        if (
          ts.isPropertyAssignment(node) &&
          ts.isIdentifier(node.name) &&
          node.name.escapedText === 'messages'
        ) {
          return ts.factory.updatePropertyAssignment(
            node,
            node.name,
            ts.factory.createObjectLiteralExpression([
              ts.factory.createPropertyAssignment(
                messageId,
                ts.factory.createStringLiteral(knownLintErrorMessage)
              ),
            ])
          );
        }

        /**
         * Update the rule implementation to report the knownLintErrorMessage on every Program node
         *
         * During the debugging of the switch from ts-node to swc-node we found out
         * that regular rules would work even without explicit path mapping registration,
         * but rules that import runtime functionality from within the workspace
         * would break the rule registration.
         *
         * Instead of having a static literal messageId we retreieved it via imported getMessageId method.
         *
         * i.e.
         *
         * create(context) {
         *    return  {
         *      Program(node) {
         *        context.report({
         *          messageId: getMessageId(),
         *          node,
         *        });
         *      }
         *    }
         *  }
         */
        if (
          ts.isMethodDeclaration(node) &&
          ts.isIdentifier(node.name) &&
          node.name.escapedText === 'create'
        ) {
          return ts.factory.updateMethodDeclaration(
            node,
            getDecorators(node),
            getModifiers(node),
            node.asteriskToken,
            node.name,
            node.questionToken,
            node.typeParameters,
            node.parameters,
            node.type,
            ts.factory.createBlock([
              ts.factory.createReturnStatement(
                ts.factory.createObjectLiteralExpression([
                  ts.factory.createMethodDeclaration(
                    [],
                    [],
                    undefined,
                    'Program',
                    undefined,
                    [],
                    [
                      ts.factory.createParameterDeclaration(
                        [],
                        [],
                        undefined,
                        'node',
                        undefined,
                        undefined,
                        undefined
                      ),
                    ],
                    undefined,
                    ts.factory.createBlock([
                      ts.factory.createExpressionStatement(
                        ts.factory.createCallExpression(
                          ts.factory.createPropertyAccessExpression(
                            ts.factory.createIdentifier('context'),
                            'report'
                          ),
                          [],
                          [
                            ts.factory.createObjectLiteralExpression([
                              ts.factory.createPropertyAssignment(
                                'messageId',
                                ts.factory.createCallExpression(
                                  ts.factory.createIdentifier(libMethodName),
                                  [],
                                  []
                                )
                              ),
                              ts.factory.createShorthandPropertyAssignment(
                                'node'
                              ),
                            ]),
                          ]
                        )
                      ),
                    ])
                  ),
                ])
              ),
            ])
          );
        }

        return ts.visitEachChild(node, visit, context);
      }
      /**
       * Add lib import as a first line of the rule file.
       * Needed for the access of getMessageId in the context report above.
       *
       * i.e.
       *
       * import { getMessageId } from "@myproj/mylib";
       *
       */
      const importAdded = ts.factory.updateSourceFile(rootNode, [
        ts.factory.createImportDeclaration(
          undefined,
          undefined,
          ts.factory.createImportClause(
            false,
            undefined,
            ts.factory.createNamedImports([
              ts.factory.createImportSpecifier(
                false,
                undefined,
                ts.factory.createIdentifier(libMethodName)
              ),
            ])
          ),
          ts.factory.createStringLiteral(libPath)
        ),
        ...rootNode.statements,
      ]);
      return ts.visitNode(importAdded, visit);
    };

  const result: ts.TransformationResult<ts.SourceFile> =
    ts.transform<ts.SourceFile>(newRuleSourceFile, [transformer]);
  const updatedSourceFile: ts.SourceFile = result.transformed[0];

  return printer.printFile(updatedSourceFile);
}