angular-docs-cn/packages/core/schematics/migrations/template-var-assignment/index.ts

88 lines
3.3 KiB
TypeScript

/**
* @license
* Copyright Google LLC 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 {logging, normalize} from '@angular-devkit/core';
import {Rule, SchematicContext, SchematicsException, Tree} from '@angular-devkit/schematics';
import {relative} from 'path';
import {NgComponentTemplateVisitor} from '../../utils/ng_component_template';
import {getProjectTsConfigPaths} from '../../utils/project_tsconfig_paths';
import {createMigrationProgram} from '../../utils/typescript/compiler_host';
import {analyzeResolvedTemplate} from './analyze_template';
type Logger = logging.LoggerApi;
const README_URL = 'https://v8.angular.io/guide/deprecations#cannot-assign-to-template-variables';
const FAILURE_MESSAGE = `Found assignment to template variable.`;
/** Entry point for the V8 template variable assignment schematic. */
export default function(): Rule {
return (tree: Tree, context: SchematicContext) => {
const {buildPaths, testPaths} = getProjectTsConfigPaths(tree);
const basePath = process.cwd();
if (!buildPaths.length && !testPaths.length) {
throw new SchematicsException(
'Could not find any tsconfig file. Cannot check templates for template variable ' +
'assignments.');
}
for (const tsconfigPath of [...buildPaths, ...testPaths]) {
runTemplateVariableAssignmentCheck(tree, tsconfigPath, basePath, context.logger);
}
};
}
/**
* Runs the template variable assignment check. Warns developers
* if values are assigned to template variables within output bindings.
*/
function runTemplateVariableAssignmentCheck(
tree: Tree, tsconfigPath: string, basePath: string, logger: Logger) {
const {program} = createMigrationProgram(tree, tsconfigPath, basePath);
const typeChecker = program.getTypeChecker();
const templateVisitor = new NgComponentTemplateVisitor(typeChecker);
const sourceFiles = program.getSourceFiles().filter(
f => !f.isDeclarationFile && !program.isSourceFileFromExternalLibrary(f));
// Analyze source files by detecting HTML templates.
sourceFiles.forEach(sourceFile => templateVisitor.visitNode(sourceFile));
const {resolvedTemplates} = templateVisitor;
const collectedFailures: string[] = [];
// Analyze each resolved template and print a warning for property writes to
// template variables.
resolvedTemplates.forEach(template => {
const filePath = template.filePath;
const nodes = analyzeResolvedTemplate(template);
if (!nodes) {
return;
}
const displayFilePath = normalize(relative(basePath, filePath));
nodes.forEach(n => {
const {line, character} = template.getCharacterAndLineOfPosition(n.start);
collectedFailures.push(`${displayFilePath}@${line + 1}:${character + 1}: ${FAILURE_MESSAGE}`);
});
});
if (collectedFailures.length) {
logger.info('---- Template Variable Assignment schematic ----');
logger.info('Assignments to template variables will no longer work with Ivy as');
logger.info('template variables are effectively constants in Ivy. Read more about');
logger.info(`this change here: ${README_URL}`);
logger.info('');
logger.info('The following template assignments were found:');
collectedFailures.forEach(failure => logger.warn(`${failure}`));
}
}