feat(@angular-devkit/schematics): allow path template to have propert…

…y accessors Path templates now allow dots (".") to be used to access properties. Fixes angular#12446
hansl · Oct 2, 2018 · 734935f · 734935f
1 parent ab1dfd0
commit 734935f
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diff --git a/packages/angular_devkit/schematics/src/rules/template.ts b/packages/angular_devkit/schematics/src/rules/template.ts
@@ -16,6 +16,13 @@ import { isBinary } from './utils/is-binary';
 export const TEMPLATE_FILENAME_RE = /\.template$/;
 
 
+export class InvalidPropertyAccessException extends BaseException {
+  constructor(_name: string, accessor: string) {
+    super(`Invalid property access in path: ${accessor} is invalid.`);
+  }
+}
+
+
 export class OptionIsNotDefinedException extends BaseException {
   constructor(name: string) { super(`Option "${name}" is not defined.`); }
 }
@@ -46,6 +53,9 @@ export interface PathTemplateOptions {
 
   // Separator for pipes. Do not specify to remove pipe support.
   pipeSeparator?: string;
+
+  // Separator for property access.
+  propertySeparator?: string;
 }
 
 
@@ -75,6 +85,7 @@ export function applyPathTemplate<T extends PathTemplateData>(
     interpolationStart: '__',
     interpolationEnd: '__',
     pipeSeparator: '@',
+    propertySeparator: '.',
   },
 ): FileOperator {
   const is = options.interpolationStart;
@@ -105,7 +116,23 @@ export function applyPathTemplate<T extends PathTemplateData>(
         }
       } else {
         const [name, ...pipes] = match.split(options.pipeSeparator);
-        replacement = data[name];
+
+        // Additionally, we check if we can do evaluation of a simple JS path here.
+        // This only supports `.`. For access in arrays, use `.0` for example for the first
+        // element. This is to avoid invalid character on some platforms (`[]`).
+        // The ultimate value is coerced to string below, though.
+        if (!options.propertySeparator) {
+          replacement = data[name];
+        } else {
+          replacement = name.split(options.propertySeparator)
+            .reduce((previous, curr) => {
+              if (typeof previous !== 'object' || previous[curr] === null) {
+                throw new InvalidPropertyAccessException(curr, name);
+              }
+
+              return previous[curr];
+            }, data);
+        }
 
         if (typeof replacement == 'function') {
           replacement = replacement.call(data, original);

diff --git a/packages/angular_devkit/schematics/src/rules/template_spec.ts b/packages/angular_devkit/schematics/src/rules/template_spec.ts
@@ -15,6 +15,7 @@ import { FileEntry, MergeStrategy } from '../tree/interface';
 import { callRule } from './call';
 import {
   InvalidPipeException,
+  InvalidPropertyAccessException,
   OptionIsNotDefinedException,
   UnknownPipeException,
   applyContentTemplate,
@@ -54,6 +55,9 @@ describe('applyPathTemplate', () => {
     expect(_applyPathTemplate('/a/b/__c__/d', { c: 'hello/world' })).toBe('/a/b/hello/world/d');
     expect(_applyPathTemplate('/a__c__b', { c: 'hello/world' })).toBe('/ahello/worldb');
     expect(_applyPathTemplate('/a__c__b__d__c', { c: '1', d: '2' })).toBe('/a1b2c');
+    expect(_applyPathTemplate('/a__c.d__b__d__c', { c: { d: '1' }, d: '2' })).toBe('/a1b2c');
+    expect(_applyPathTemplate('/a__c.d.e.f__b__d__c', { c: { d: { e: { f: '1' } } }, d: '2' }))
+      .toBe('/a1b2c');
   });
 
   it('works with single _', () => {
@@ -112,6 +116,11 @@ describe('applyPathTemplate', () => {
     expect(() => _applyPathTemplate('/a__b@d__c', { b: 1, d: 1 }))
       .toThrow(new InvalidPipeException('d'));
   });
+
+  it('errors invalid accessors', () => {
+    expect(() => _applyPathTemplate('/a__a.b__c', { a: { b: null } }))
+      .toThrow(new InvalidPropertyAccessException('a', 'a.b'));
+  });
 });