angular-cn/packages/core/schematics/migrations/injectable-pipe/util.ts

48 lines
1.7 KiB
TypeScript

/**
* @license
* Copyright Google Inc. All Rights Reserved.
*
* Use of this source code is governed by an MIT-style license that can be
* found in the LICENSE file at https://angular.io/license
*/
import * as ts from 'typescript';
/** Name of the Injectable decorator. */
export const INJECTABLE_DECORATOR_NAME = 'Injectable';
/**
* Adds a named import to an import declaration node.
* @param node Node to which to add the import.
* @param importName Name of the import that should be added.
*/
export function addNamedImport(node: ts.ImportDeclaration, importName: string) {
const namedImports = getNamedImports(node);
if (namedImports && ts.isNamedImports(namedImports)) {
const elements = namedImports.elements;
const isAlreadyImported = elements.some(element => element.name.text === importName);
if (!isAlreadyImported) {
// If there are named imports, there will be an import clause as well.
const importClause = node.importClause !;
const newImportClause = ts.createNamedImports(
[...elements, ts.createImportSpecifier(undefined, ts.createIdentifier(importName))]);
return ts.updateImportDeclaration(
node, node.decorators, node.modifiers,
ts.updateImportClause(importClause, importClause.name, newImportClause),
node.moduleSpecifier);
}
}
return node;
}
/** Gets the named imports node from an import declaration. */
export function getNamedImports(node: ts.ImportDeclaration): ts.NamedImports|null {
const importClause = node.importClause;
const namedImports = importClause && importClause.namedBindings;
return (namedImports && ts.isNamedImports(namedImports)) ? namedImports : null;
}