angular-cn/packages/language-service/common/definitions.ts

95 lines
3.4 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 * as path from 'path';
import * as ts from 'typescript';
import {findTightestNode, getClassDeclFromDecoratorProp, getPropertyAssignmentFromValue} from './ts_utils';
/**
* Gets an Angular-specific definition in a TypeScript source file.
*/
export function getTsDefinitionAndBoundSpan(
sf: ts.SourceFile, position: number,
tsLsHost: Pick<ts.LanguageServiceHost, 'fileExists'>): ts.DefinitionInfoAndBoundSpan|undefined {
const node = findTightestNode(sf, position);
if (!node) return;
switch (node.kind) {
case ts.SyntaxKind.StringLiteral:
case ts.SyntaxKind.NoSubstitutionTemplateLiteral:
// Attempt to extract definition of a URL in a property assignment.
return getUrlFromProperty(node as ts.StringLiteralLike, tsLsHost);
default:
return undefined;
}
}
/**
* Attempts to get the definition of a file whose URL is specified in a property assignment in a
* directive decorator.
* Currently applies to `templateUrl` and `styleUrls` properties.
*/
function getUrlFromProperty(
urlNode: ts.StringLiteralLike,
tsLsHost: Pick<ts.LanguageServiceHost, 'fileExists'>): ts.DefinitionInfoAndBoundSpan|undefined {
// Get the property assignment node corresponding to the `templateUrl` or `styleUrls` assignment.
// These assignments are specified differently; `templateUrl` is a string, and `styleUrls` is
// an array of strings:
// {
// templateUrl: './template.ng.html',
// styleUrls: ['./style.css', './other-style.css']
// }
// `templateUrl`'s property assignment can be found from the string literal node;
// `styleUrls`'s property assignment can be found from the array (parent) node.
//
// First search for `templateUrl`.
let asgn = getPropertyAssignmentFromValue(urlNode, 'templateUrl');
if (!asgn) {
// `templateUrl` assignment not found; search for `styleUrls` array assignment.
asgn = getPropertyAssignmentFromValue(urlNode.parent, 'styleUrls');
if (!asgn) {
// Nothing found, bail.
return;
}
}
// If the property assignment is not a property of a class decorator, don't generate definitions
// for it.
if (!getClassDeclFromDecoratorProp(asgn)) {
return;
}
const sf = urlNode.getSourceFile();
// Extract url path specified by the url node, which is relative to the TypeScript source file
// the url node is defined in.
const url = path.join(path.dirname(sf.fileName), urlNode.text);
// If the file does not exist, bail. It is possible that the TypeScript language service host
// does not have a `fileExists` method, in which case optimistically assume the file exists.
if (tsLsHost.fileExists && !tsLsHost.fileExists(url)) return;
const templateDefinitions: ts.DefinitionInfo[] = [{
kind: ts.ScriptElementKind.externalModuleName,
name: url,
containerKind: ts.ScriptElementKind.unknown,
containerName: '',
// Reading the template is expensive, so don't provide a preview.
textSpan: {start: 0, length: 0},
fileName: url,
}];
return {
definitions: templateDefinitions,
textSpan: {
// Exclude opening and closing quotes in the url span.
start: urlNode.getStart() + 1,
length: urlNode.getWidth() - 2,
},
};
}