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

99 lines
3.8 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 {logging, normalize} from '@angular-devkit/core';
import {Rule, SchematicContext, SchematicsException, Tree} from '@angular-devkit/schematics';
import {dirname, relative} from 'path';
import * as ts from 'typescript';
import {getProjectTsConfigPaths} from '../../utils/project_tsconfig_paths';
import {parseTsconfigFile} from '../../utils/typescript/parse_tsconfig';
import {analyzeResolvedTemplate} from './analyze_template';
import {NgComponentTemplateVisitor} from '../../utils/ng_component_template';
type Logger = logging.LoggerApi;
const README_URL =
'https://github.com/angular/angular/tree/master/packages/core/schematics/migrations/template-var-assignment/README.md';
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 projectTsConfigPaths = getProjectTsConfigPaths(tree);
const basePath = process.cwd();
if (!projectTsConfigPaths.length) {
throw new SchematicsException(
'Could not find any tsconfig file. Cannot check templates for template variable ' +
'assignments.');
}
for (const tsconfigPath of projectTsConfigPaths) {
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 parsed = parseTsconfigFile(tsconfigPath, dirname(tsconfigPath));
const host = ts.createCompilerHost(parsed.options, true);
// We need to overwrite the host "readFile" method, as we want the TypeScript
// program to be based on the file contents in the virtual file tree.
host.readFile = fileName => {
const buffer = tree.read(relative(basePath, fileName));
return buffer ? buffer.toString() : undefined;
};
const program = ts.createProgram(parsed.fileNames, parsed.options, host);
const typeChecker = program.getTypeChecker();
const templateVisitor = new NgComponentTemplateVisitor(typeChecker);
const rootSourceFiles = program.getRootFileNames().map(f => program.getSourceFile(f) !);
// Analyze source files by detecting HTML templates.
rootSourceFiles.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, filePath) => {
const nodes = analyzeResolvedTemplate(filePath, 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}`));
logger.info('------------------------------------------------');
}
}