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refactor(@schematics/angular): move standalone component helpers to a…
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… private export for Angular components

The standalone component helper utilities introduced into the `@angular/cdk` via
angular/components#24931 have been added to an export path (`private/components`)
within `@schematics/angular`. The export path is primarily intended for the use of the components schematics
within `@angular/cdk` and `@angular/material`. The API exported from this path is not considered public API,
does not provide SemVer guarantees, and may be modified or removed without a deprecation cycle.
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clydin authored and dgp1130 committed May 26, 2022
1 parent d79176e commit e895fc7
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3 changes: 2 additions & 1 deletion packages/schematics/angular/package.json
Expand Up @@ -13,7 +13,8 @@
"./utility": "./utility/index.js",
"./utility/*": "./utility/*.js",
"./migrations/migration-collection.json": "./migrations/migration-collection.json",
"./*": "./*.js"
"./*": "./*.js",
"./private/components": "./private/components.js"
},
"schematics": "./collection.json",
"dependencies": {
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13 changes: 13 additions & 0 deletions packages/schematics/angular/private/components.ts
@@ -0,0 +1,13 @@
/**
* @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
*/

export {
addModuleImportToStandaloneBootstrap,
findBootstrapApplicationCall,
importsProvidersFrom,
} from './standalone';
277 changes: 277 additions & 0 deletions packages/schematics/angular/private/standalone.ts
@@ -0,0 +1,277 @@
/**
* @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 { SchematicsException, Tree } from '@angular-devkit/schematics';
import ts from '../third_party/github.com/Microsoft/TypeScript/lib/typescript';
import { insertImport } from '../utility/ast-utils';
import { InsertChange } from '../utility/change';

/**
* Checks whether the providers from a module are being imported in a `bootstrapApplication` call.
* @param tree File tree of the project.
* @param filePath Path of the file in which to check.
* @param className Class name of the module to search for.
*/
export function importsProvidersFrom(tree: Tree, filePath: string, className: string): boolean {
const sourceFile = ts.createSourceFile(
filePath,
tree.readText(filePath),
ts.ScriptTarget.Latest,
true,
);

const bootstrapCall = findBootstrapApplicationCall(sourceFile);
const importProvidersFromCall = bootstrapCall ? findImportProvidersFromCall(bootstrapCall) : null;

return (
!!importProvidersFromCall &&
importProvidersFromCall.arguments.some((arg) => ts.isIdentifier(arg) && arg.text === className)
);
}

/**
* Adds an `importProvidersFrom` call to the `bootstrapApplication` call.
* @param tree File tree of the project.
* @param filePath Path to the file that should be updated.
* @param moduleName Name of the module that should be imported.
* @param modulePath Path from which to import the module.
*/
export function addModuleImportToStandaloneBootstrap(
tree: Tree,
filePath: string,
moduleName: string,
modulePath: string,
) {
const sourceFile = ts.createSourceFile(
filePath,
tree.readText(filePath),
ts.ScriptTarget.Latest,
true,
);

const bootstrapCall = findBootstrapApplicationCall(sourceFile);

if (!bootstrapCall) {
throw new SchematicsException(`Could not find bootstrapApplication call in ${filePath}`);
}

const recorder = tree.beginUpdate(filePath);
const importCall = findImportProvidersFromCall(bootstrapCall);
const printer = ts.createPrinter();
const sourceText = sourceFile.getText();

// Add imports to the module being added and `importProvidersFrom`. We don't
// have to worry about duplicates, because `insertImport` handles them.
[
insertImport(sourceFile, sourceText, moduleName, modulePath),
insertImport(sourceFile, sourceText, 'importProvidersFrom', '@angular/core'),
].forEach((change) => {
if (change instanceof InsertChange) {
recorder.insertLeft(change.pos, change.toAdd);
}
});

// If there is an `importProvidersFrom` call already, reuse it.
if (importCall) {
recorder.insertRight(
importCall.arguments[importCall.arguments.length - 1].getEnd(),
`, ${moduleName}`,
);
} else if (bootstrapCall.arguments.length === 1) {
// Otherwise if there is no options parameter to `bootstrapApplication`,
// create an object literal with a `providers` array and the import.
const newCall = ts.factory.updateCallExpression(
bootstrapCall,
bootstrapCall.expression,
bootstrapCall.typeArguments,
[
...bootstrapCall.arguments,
ts.factory.createObjectLiteralExpression([createProvidersAssignment(moduleName)], true),
],
);

recorder.remove(bootstrapCall.getStart(), bootstrapCall.getWidth());
recorder.insertRight(
bootstrapCall.getStart(),
printer.printNode(ts.EmitHint.Unspecified, newCall, sourceFile),
);
} else {
const providersLiteral = findProvidersLiteral(bootstrapCall);

if (providersLiteral) {
// If there's a `providers` array, add the import to it.
const newProvidersLiteral = ts.factory.updateArrayLiteralExpression(providersLiteral, [
...providersLiteral.elements,
createImportProvidersFromCall(moduleName),
]);
recorder.remove(providersLiteral.getStart(), providersLiteral.getWidth());
recorder.insertRight(
providersLiteral.getStart(),
printer.printNode(ts.EmitHint.Unspecified, newProvidersLiteral, sourceFile),
);
} else {
// Otherwise add a `providers` array to the existing object literal.
const optionsLiteral = bootstrapCall.arguments[1] as ts.ObjectLiteralExpression;
const newOptionsLiteral = ts.factory.updateObjectLiteralExpression(optionsLiteral, [
...optionsLiteral.properties,
createProvidersAssignment(moduleName),
]);
recorder.remove(optionsLiteral.getStart(), optionsLiteral.getWidth());
recorder.insertRight(
optionsLiteral.getStart(),
printer.printNode(ts.EmitHint.Unspecified, newOptionsLiteral, sourceFile),
);
}
}

tree.commitUpdate(recorder);
}

/** Finds the call to `bootstrapApplication` within a file. */
export function findBootstrapApplicationCall(sourceFile: ts.SourceFile): ts.CallExpression | null {
const localName = findImportLocalName(
sourceFile,
'bootstrapApplication',
'@angular/platform-browser',
);

return localName ? findCall(sourceFile, localName) : null;
}

/** Find a call to `importProvidersFrom` within a `bootstrapApplication` call. */
function findImportProvidersFromCall(bootstrapCall: ts.CallExpression): ts.CallExpression | null {
const providersLiteral = findProvidersLiteral(bootstrapCall);
const importProvidersName = findImportLocalName(
bootstrapCall.getSourceFile(),
'importProvidersFrom',
'@angular/core',
);

if (providersLiteral && importProvidersName) {
for (const element of providersLiteral.elements) {
// Look for an array element that calls the `importProvidersFrom` function.
if (
ts.isCallExpression(element) &&
ts.isIdentifier(element.expression) &&
element.expression.text === importProvidersName
) {
return element;
}
}
}

return null;
}

/** Finds the `providers` array literal within a `bootstrapApplication` call. */
function findProvidersLiteral(bootstrapCall: ts.CallExpression): ts.ArrayLiteralExpression | null {
// The imports have to be in the second argument of
// the function which has to be an object literal.
if (
bootstrapCall.arguments.length > 1 &&
ts.isObjectLiteralExpression(bootstrapCall.arguments[1])
) {
for (const prop of bootstrapCall.arguments[1].properties) {
if (
ts.isPropertyAssignment(prop) &&
ts.isIdentifier(prop.name) &&
prop.name.text === 'providers' &&
ts.isArrayLiteralExpression(prop.initializer)
) {
return prop.initializer;
}
}
}

return null;
}

/**
* Finds the local name of an imported symbol. Could be the symbol name itself or its alias.
* @param sourceFile File within which to search for the import.
* @param name Actual name of the import, not its local alias.
* @param moduleName Name of the module from which the symbol is imported.
*/
function findImportLocalName(
sourceFile: ts.SourceFile,
name: string,
moduleName: string,
): string | null {
for (const node of sourceFile.statements) {
// Only look for top-level imports.
if (
!ts.isImportDeclaration(node) ||
!ts.isStringLiteral(node.moduleSpecifier) ||
node.moduleSpecifier.text !== moduleName
) {
continue;
}

// Filter out imports that don't have the right shape.
if (
!node.importClause ||
!node.importClause.namedBindings ||
!ts.isNamedImports(node.importClause.namedBindings)
) {
continue;
}

// Look through the elements of the declaration for the specific import.
for (const element of node.importClause.namedBindings.elements) {
if ((element.propertyName || element.name).text === name) {
// The local name is always in `name`.
return element.name.text;
}
}
}

return null;
}

/**
* Finds a call to a function with a specific name.
* @param rootNode Node from which to start searching.
* @param name Name of the function to search for.
*/
function findCall(rootNode: ts.Node, name: string): ts.CallExpression | null {
let result: ts.CallExpression | null = null;

rootNode.forEachChild(function walk(node) {
if (
ts.isCallExpression(node) &&
ts.isIdentifier(node.expression) &&
node.expression.text === name
) {
result = node;
}

if (!result) {
node.forEachChild(walk);
}
});

return result;
}

/** Creates an `importProvidersFrom({{moduleName}})` call. */
function createImportProvidersFromCall(moduleName: string): ts.CallExpression {
return ts.factory.createCallChain(
ts.factory.createIdentifier('importProvidersFrom'),
undefined,
undefined,
[ts.factory.createIdentifier(moduleName)],
);
}

/** Creates a `providers: [importProvidersFrom({{moduleName}})]` property assignment. */
function createProvidersAssignment(moduleName: string): ts.PropertyAssignment {
return ts.factory.createPropertyAssignment(
'providers',
ts.factory.createArrayLiteralExpression([createImportProvidersFromCall(moduleName)]),
);
}

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