fix: Find uses of translate pipe in pipe arguments (bartholomej#2)

* refactor(pipe-parser) simplify handling of pipes in getTranslatablesFromAst

remove expressionIsOrHasBindingPipe - previously this also handled cases like `'World' | translate | upper`,
but it's not actually needed, getTranslatablesFromAst can deal with it by itself

move checks for translate and non-translate pipes together under a common BindingPipe check.

* fix(pipe-parser): find usages of translate pipe in arguments of other pipes

src/parsers/pipe.parser.ts

@@ -96,11 +96,19 @@ export class PipeParser implements ParserInterface {
 	}
 
 	protected getTranslatablesFromAst(ast: AST): BindingPipe[] {
-		// the entire expression is the translate pipe, e.g.:
-		// - 'foo' | translate
-		// - (condition ? 'foo' : 'bar') | translate
-		if (this.expressionIsOrHasBindingPipe(ast)) {
-			return [ast];
+		if (ast instanceof BindingPipe) {
+			// the entire expression is the translate pipe, e.g.:
+			// - 'foo' | translate
+			// - (condition ? 'foo' : 'bar') | translate
+			if (ast.name === TRANSLATE_PIPE_NAME) {
+				// also visit the pipe arguments - interpolateParams object
+				return [ast, ...this.getTranslatablesFromAsts(ast.args)];
+			}
+
+			// not the translate pipe - ignore the pipe, visit the expression and arguments, e.g.:
+			// - { foo: 'Hello' | translate } | json
+			// - value | date: ('mediumDate' | translate)
+			return this.getTranslatablesFromAsts([ast.exp, ...ast.args]);
 		}
 
 		// angular double curly bracket interpolation, e.g.:
@@ -124,12 +132,6 @@ export class PipeParser implements ParserInterface {
 			}
 		}
 
-		// a pipe on the outer expression, but not the translate pipe - ignore the pipe, visit the expression, e.g.:
-		// - { foo: 'Hello' | translate } | json
-		if (ast instanceof BindingPipe) {
-			return this.getTranslatablesFromAst(ast.exp);
-		}
-
 		// object - ignore the keys, visit all values, e.g.:
 		// - { key1: 'value1' | translate, key2: 'value2' | translate }
 		if (ast instanceof LiteralMap) {
@@ -157,16 +159,6 @@ export class PipeParser implements ParserInterface {
 		return [].concat(...array);
 	}
 
-	protected expressionIsOrHasBindingPipe(exp: any): exp is BindingPipe {
-		if (exp.name && exp.name === TRANSLATE_PIPE_NAME) {
-			return true;
-		}
-		if (exp.exp && exp.exp instanceof BindingPipe) {
-			return this.expressionIsOrHasBindingPipe(exp.exp);
-		}
-		return false;
-	}
-
 	protected parseTemplate(template: string, path: string): TmplAstNode[] {
 		return parseTemplate(template, path).nodes;
 	}

tests/parsers/pipe.parser.spec.ts

@@ -196,6 +196,18 @@ describe('PipeParser', () => {
 		expect(keys).to.deep.equal([]);
 	});
 
+	it('should extract translate pipe used as pipe argument', () => {
+		const contents = `{{ value | valueToTranslationKey: ('argument' | translate) }}`;
+		const keys = parser.extract(contents, templateFilename).keys();
+		expect(keys).to.deep.equal(['argument']);
+	});
+
+	it('should extract nested uses of translate pipe', () => {
+		const contents = `{{ 'Hello' | translate: {world: ('World' | translate)} }}`;
+		const keys = parser.extract(contents, templateFilename).keys();
+		expect(keys).to.deep.equal(['Hello', 'World']);
+	});
+
 	it('should extract strings from piped arguments inside a function calls on templates', () => {
 		const contents = `{{ callMe('Hello' | translate, 'World' | translate ) }}`;
 		const keys = parser.extract(contents, templateFilename).keys();