angular-docs-cn/packages/compiler/test/expression_parser/parser_spec.ts

603 lines
21 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 {ASTWithSource, BindingPipe, Interpolation, ParserError, TemplateBinding} from '@angular/compiler/src/expression_parser/ast';
import {Lexer} from '@angular/compiler/src/expression_parser/lexer';
import {Parser, SplitInterpolation, TemplateBindingParseResult} from '@angular/compiler/src/expression_parser/parser';
import {expect} from '@angular/platform-browser/testing/src/matchers';
import {unparse} from './utils/unparser';
import {validate} from './utils/validator';
describe('parser', () => {
describe('parseAction', () => {
it('should parse numbers', () => { checkAction('1'); });
it('should parse strings', () => {
checkAction('\'1\'', '"1"');
checkAction('"1"');
});
it('should parse null', () => { checkAction('null'); });
it('should parse undefined', () => { checkAction('undefined'); });
it('should parse unary - expressions', () => {
checkAction('-1', '0 - 1');
checkAction('+1', '1 - 0');
checkAction(`-'1'`, `0 - "1"`);
checkAction(`+'1'`, `"1" - 0`);
});
it('should parse unary ! expressions', () => {
checkAction('!true');
checkAction('!!true');
checkAction('!!!true');
});
it('should parse postfix ! expression', () => {
checkAction('true!');
checkAction('a!.b');
checkAction('a!!!!.b');
});
it('should parse multiplicative expressions',
() => { checkAction('3*4/2%5', '3 * 4 / 2 % 5'); });
it('should parse additive expressions', () => { checkAction('3 + 6 - 2'); });
it('should parse relational expressions', () => {
checkAction('2 < 3');
checkAction('2 > 3');
checkAction('2 <= 2');
checkAction('2 >= 2');
});
it('should parse equality expressions', () => {
checkAction('2 == 3');
checkAction('2 != 3');
});
it('should parse strict equality expressions', () => {
checkAction('2 === 3');
checkAction('2 !== 3');
});
it('should parse expressions', () => {
checkAction('true && true');
checkAction('true || false');
});
it('should parse grouped expressions', () => { checkAction('(1 + 2) * 3', '1 + 2 * 3'); });
it('should ignore comments in expressions', () => { checkAction('a //comment', 'a'); });
it('should retain // in string literals',
() => { checkAction(`"http://www.google.com"`, `"http://www.google.com"`); });
it('should parse an empty string', () => { checkAction(''); });
describe('literals', () => {
it('should parse array', () => {
checkAction('[1][0]');
checkAction('[[1]][0][0]');
checkAction('[]');
checkAction('[].length');
checkAction('[1, 2].length');
});
it('should parse map', () => {
checkAction('{}');
checkAction('{a: 1, "b": 2}[2]');
checkAction('{}["a"]');
});
it('should only allow identifier, string, or keyword as map key', () => {
expectActionError('{(:0}', 'expected identifier, keyword, or string');
expectActionError('{1234:0}', 'expected identifier, keyword, or string');
});
});
describe('member access', () => {
it('should parse field access', () => {
checkAction('a');
checkAction('this.a', 'a');
checkAction('a.a');
});
it('should only allow identifier or keyword as member names', () => {
expectActionError('x.(', 'identifier or keyword');
expectActionError('x. 1234', 'identifier or keyword');
expectActionError('x."foo"', 'identifier or keyword');
});
it('should parse safe field access', () => {
checkAction('a?.a');
checkAction('a.a?.a');
});
});
describe('method calls', () => {
it('should parse method calls', () => {
checkAction('fn()');
checkAction('add(1, 2)');
checkAction('a.add(1, 2)');
checkAction('fn().add(1, 2)');
});
});
describe('functional calls', () => {
it('should parse function calls', () => { checkAction('fn()(1, 2)'); });
});
describe('conditional', () => {
it('should parse ternary/conditional expressions', () => {
checkAction('7 == 3 + 4 ? 10 : 20');
checkAction('false ? 10 : 20');
});
it('should report incorrect ternary operator syntax', () => {
expectActionError('true?1', 'Conditional expression true?1 requires all 3 expressions');
});
});
describe('assignment', () => {
it('should support field assignments', () => {
checkAction('a = 12');
checkAction('a.a.a = 123');
checkAction('a = 123; b = 234;');
});
it('should report on safe field assignments',
() => { expectActionError('a?.a = 123', 'cannot be used in the assignment'); });
it('should support array updates', () => { checkAction('a[0] = 200'); });
});
it('should error when using pipes',
() => { expectActionError('x|blah', 'Cannot have a pipe'); });
it('should store the source in the result',
() => { expect(parseAction('someExpr', 'someExpr')); });
it('should store the passed-in location',
() => { expect(parseAction('someExpr', 'location').location).toBe('location'); });
it('should report when encountering interpolation', () => {
expectActionError('{{a()}}', 'Got interpolation ({{}}) where expression was expected');
});
});
describe('general error handling', () => {
it('should report an unexpected token',
() => { expectActionError('[1,2] trac', 'Unexpected token \'trac\''); });
it('should report reasonable error for unconsumed tokens',
() => { expectActionError(')', 'Unexpected token ) at column 1 in [)]'); });
it('should report a missing expected token', () => {
expectActionError('a(b', 'Missing expected ) at the end of the expression [a(b]');
});
});
describe('parseBinding', () => {
describe('pipes', () => {
it('should parse pipes', () => {
checkBinding('a(b | c)', 'a((b | c))');
checkBinding('a.b(c.d(e) | f)', 'a.b((c.d(e) | f))');
checkBinding('[1, 2, 3] | a', '([1, 2, 3] | a)');
checkBinding('{a: 1, "b": 2} | c', '({a: 1, "b": 2} | c)');
checkBinding('a[b] | c', '(a[b] | c)');
checkBinding('a?.b | c', '(a?.b | c)');
checkBinding('true | a', '(true | a)');
checkBinding('a | b:c | d', '((a | b:c) | d)');
checkBinding('a | b:(c | d)', '(a | b:(c | d))');
});
it('should only allow identifier or keyword as formatter names', () => {
expectBindingError('"Foo"|(', 'identifier or keyword');
expectBindingError('"Foo"|1234', 'identifier or keyword');
expectBindingError('"Foo"|"uppercase"', 'identifier or keyword');
});
it('should parse quoted expressions', () => { checkBinding('a:b', 'a:b'); });
it('should not crash when prefix part is not tokenizable',
() => { checkBinding('"a:b"', '"a:b"'); });
it('should ignore whitespace around quote prefix', () => { checkBinding(' a :b', 'a:b'); });
it('should refuse prefixes that are not single identifiers', () => {
expectBindingError('a + b:c', '');
expectBindingError('1:c', '');
});
});
it('should store the source in the result',
() => { expect(parseBinding('someExpr').source).toBe('someExpr'); });
it('should store the passed-in location',
() => { expect(parseBinding('someExpr', 'location').location).toBe('location'); });
it('should report chain expressions',
() => { expectError(parseBinding('1;2'), 'contain chained expression'); });
it('should report assignment',
() => { expectError(parseBinding('a=2'), 'contain assignments'); });
it('should report when encountering interpolation', () => {
expectBindingError('{{a.b}}', 'Got interpolation ({{}}) where expression was expected');
});
it('should parse conditional expression', () => { checkBinding('a < b ? a : b'); });
it('should ignore comments in bindings', () => { checkBinding('a //comment', 'a'); });
it('should retain // in string literals',
() => { checkBinding(`"http://www.google.com"`, `"http://www.google.com"`); });
it('should retain // in : microsyntax', () => { checkBinding('one:a//b', 'one:a//b'); });
});
describe('parseTemplateBindings', () => {
function keys(templateBindings: any[]) { return templateBindings.map(binding => binding.key); }
function keyValues(templateBindings: any[]) {
return templateBindings.map(binding => {
if (binding.keyIsVar) {
return 'let ' + binding.key + (binding.name == null ? '=null' : '=' + binding.name);
} else {
return binding.key + (binding.expression == null ? '' : `=${binding.expression}`);
}
});
}
function keySpans(source: string, templateBindings: TemplateBinding[]) {
return templateBindings.map(
binding => source.substring(binding.span.start, binding.span.end));
}
function exprSources(templateBindings: any[]) {
return templateBindings.map(
binding => binding.expression != null ? binding.expression.source : null);
}
it('should parse a key without a value',
() => { expect(keys(parseTemplateBindings('a', ''))).toEqual(['a']); });
it('should allow string including dashes as keys', () => {
let bindings = parseTemplateBindings('a', 'b');
expect(keys(bindings)).toEqual(['a']);
bindings = parseTemplateBindings('a-b', 'c');
expect(keys(bindings)).toEqual(['a-b']);
});
it('should detect expressions as value', () => {
let bindings = parseTemplateBindings('a', 'b');
expect(exprSources(bindings)).toEqual(['b']);
bindings = parseTemplateBindings('a', '1+1');
expect(exprSources(bindings)).toEqual(['1+1']);
});
it('should detect names as value', () => {
const bindings = parseTemplateBindings('a', 'let b');
expect(keyValues(bindings)).toEqual(['a', 'let b=$implicit']);
});
it('should allow space and colon as separators', () => {
let bindings = parseTemplateBindings('a', 'b');
expect(keys(bindings)).toEqual(['a']);
expect(exprSources(bindings)).toEqual(['b']);
});
it('should allow multiple pairs', () => {
const bindings = parseTemplateBindings('a', '1 b 2');
expect(keys(bindings)).toEqual(['a', 'aB']);
expect(exprSources(bindings)).toEqual(['1 ', '2']);
});
it('should store the sources in the result', () => {
const bindings = parseTemplateBindings('a', '1,b 2');
expect(bindings[0].expression !.source).toEqual('1');
expect(bindings[1].expression !.source).toEqual('2');
});
it('should store the passed-in location', () => {
const bindings = parseTemplateBindings('a', '1,b 2', 'location');
expect(bindings[0].expression !.location).toEqual('location');
});
it('should support let notation', () => {
let bindings = parseTemplateBindings('key', 'let i');
expect(keyValues(bindings)).toEqual(['key', 'let i=$implicit']);
bindings = parseTemplateBindings('key', 'let a; let b');
expect(keyValues(bindings)).toEqual([
'key',
'let a=$implicit',
'let b=$implicit',
]);
bindings = parseTemplateBindings('key', 'let a; let b;');
expect(keyValues(bindings)).toEqual([
'key',
'let a=$implicit',
'let b=$implicit',
]);
bindings = parseTemplateBindings('key', 'let i-a = k-a');
expect(keyValues(bindings)).toEqual([
'key',
'let i-a=k-a',
]);
bindings = parseTemplateBindings('key', 'let item; let i = k');
expect(keyValues(bindings)).toEqual([
'key',
'let item=$implicit',
'let i=k',
]);
bindings = parseTemplateBindings('directive', 'let item in expr; let a = b', 'location');
expect(keyValues(bindings)).toEqual([
'directive',
'let item=$implicit',
'directiveIn=expr in location',
'let a=b',
]);
});
it('should support as notation', () => {
let bindings = parseTemplateBindings('ngIf', 'exp as local', 'location');
expect(keyValues(bindings)).toEqual(['ngIf=exp in location', 'let local=ngIf']);
bindings = parseTemplateBindings('ngFor', 'let item of items as iter; index as i', 'L');
expect(keyValues(bindings)).toEqual([
'ngFor', 'let item=$implicit', 'ngForOf=items in L', 'let iter=ngForOf', 'let i=index'
]);
});
it('should parse pipes', () => {
const bindings = parseTemplateBindings('key', 'value|pipe');
const ast = bindings[0].expression !.ast;
expect(ast).toBeAnInstanceOf(BindingPipe);
});
describe('spans', () => {
it('should should support let', () => {
const source = 'let i';
expect(keySpans(source, parseTemplateBindings('key', 'let i'))).toEqual(['', 'let i']);
});
it('should support multiple lets', () => {
const source = 'let item; let i=index; let e=even;';
expect(keySpans(source, parseTemplateBindings('key', source))).toEqual([
'', 'let item', 'let i=index', 'let e=even'
]);
});
it('should support a prefix', () => {
const source = 'let person of people';
const prefix = 'ngFor';
const bindings = parseTemplateBindings(prefix, source);
expect(keyValues(bindings)).toEqual([
'ngFor', 'let person=$implicit', 'ngForOf=people in null'
]);
expect(keySpans(source, bindings)).toEqual(['', 'let person ', 'of people']);
});
});
});
describe('parseInterpolation', () => {
it('should return null if no interpolation',
() => { expect(parseInterpolation('nothing')).toBe(null); });
it('should parse no prefix/suffix interpolation', () => {
const ast = parseInterpolation('{{a}}') !.ast as Interpolation;
expect(ast.strings).toEqual(['', '']);
expect(ast.expressions.length).toEqual(1);
expect(ast.expressions[0].name).toEqual('a');
});
it('should parse prefix/suffix with multiple interpolation', () => {
const originalExp = 'before {{ a }} middle {{ b }} after';
const ast = parseInterpolation(originalExp) !.ast;
expect(unparse(ast)).toEqual(originalExp);
validate(ast);
});
it('should report empty interpolation expressions', () => {
expectError(
parseInterpolation('{{}}') !,
'Blank expressions are not allowed in interpolated strings');
expectError(
parseInterpolation('foo {{ }}') !,
'Parser Error: Blank expressions are not allowed in interpolated strings');
});
it('should parse conditional expression', () => { checkInterpolation('{{ a < b ? a : b }}'); });
it('should parse expression with newline characters', () => {
checkInterpolation(`{{ 'foo' +\n 'bar' +\r 'baz' }}`, `{{ "foo" + "bar" + "baz" }}`);
});
it('should support custom interpolation', () => {
const parser = new Parser(new Lexer());
const ast =
parser.parseInterpolation('{% a %}', null, 0, {start: '{%', end: '%}'}) !.ast as any;
expect(ast.strings).toEqual(['', '']);
expect(ast.expressions.length).toEqual(1);
expect(ast.expressions[0].name).toEqual('a');
});
describe('comments', () => {
it('should ignore comments in interpolation expressions',
() => { checkInterpolation('{{a //comment}}', '{{ a }}'); });
it('should retain // in single quote strings', () => {
checkInterpolation(`{{ 'http://www.google.com' }}`, `{{ "http://www.google.com" }}`);
});
it('should retain // in double quote strings', () => {
checkInterpolation(`{{ "http://www.google.com" }}`, `{{ "http://www.google.com" }}`);
});
it('should ignore comments after string literals',
() => { checkInterpolation(`{{ "a//b" //comment }}`, `{{ "a//b" }}`); });
it('should retain // in complex strings', () => {
checkInterpolation(
`{{"//a\'//b\`//c\`//d\'//e" //comment}}`, `{{ "//a\'//b\`//c\`//d\'//e" }}`);
});
it('should retain // in nested, unterminated strings',
() => { checkInterpolation(`{{ "a\'b\`" //comment}}`, `{{ "a\'b\`" }}`); });
});
});
describe('parseSimpleBinding', () => {
it('should parse a field access', () => {
const p = parseSimpleBinding('name');
expect(unparse(p)).toEqual('name');
validate(p);
});
it('should report when encountering pipes', () => {
expectError(
validate(parseSimpleBinding('a | somePipe')),
'Host binding expression cannot contain pipes');
});
it('should report when encountering interpolation', () => {
expectError(
validate(parseSimpleBinding('{{exp}}')),
'Got interpolation ({{}}) where expression was expected');
});
it('should report when encountering field write', () => {
expectError(validate(parseSimpleBinding('a = b')), 'Bindings cannot contain assignments');
});
});
describe('wrapLiteralPrimitive', () => {
it('should wrap a literal primitive', () => {
expect(unparse(validate(createParser().wrapLiteralPrimitive('foo', null, 0))))
.toEqual('"foo"');
});
});
describe('error recovery', () => {
function recover(text: string, expected?: string) {
const expr = validate(parseAction(text));
expect(unparse(expr)).toEqual(expected || text);
}
it('should be able to recover from an extra paren', () => recover('((a)))', 'a'));
it('should be able to recover from an extra bracket', () => recover('[[a]]]', '[[a]]'));
it('should be able to recover from a missing )', () => recover('(a;b', 'a; b;'));
it('should be able to recover from a missing ]', () => recover('[a,b', '[a, b]'));
it('should be able to recover from a missing selector', () => recover('a.'));
it('should be able to recover from a missing selector in a array literal',
() => recover('[[a.], b, c]'));
});
describe('offsets', () => {
it('should retain the offsets of an interpolation', () => {
const interpolations = splitInterpolation('{{a}} {{b}} {{c}}') !;
expect(interpolations.offsets).toEqual([2, 9, 16]);
});
it('should retain the offsets into the expression AST of interpolations', () => {
const source = parseInterpolation('{{a}} {{b}} {{c}}') !;
const interpolation = source.ast as Interpolation;
expect(interpolation.expressions.map(e => e.span.start)).toEqual([2, 9, 16]);
});
});
});
function createParser() {
return new Parser(new Lexer());
}
function parseAction(text: string, location: any = null, offset: number = 0): ASTWithSource {
return createParser().parseAction(text, location, offset);
}
function parseBinding(text: string, location: any = null, offset: number = 0): ASTWithSource {
return createParser().parseBinding(text, location, offset);
}
function parseTemplateBindingsResult(
key: string, value: string, location: any = null,
offset: number = 0): TemplateBindingParseResult {
return createParser().parseTemplateBindings(key, value, location, offset);
}
function parseTemplateBindings(
key: string, value: string, location: any = null, offset: number = 0): TemplateBinding[] {
return parseTemplateBindingsResult(key, value, location).templateBindings;
}
function parseInterpolation(text: string, location: any = null, offset: number = 0): ASTWithSource|
null {
return createParser().parseInterpolation(text, location, offset);
}
function splitInterpolation(text: string, location: any = null): SplitInterpolation|null {
return createParser().splitInterpolation(text, location);
}
function parseSimpleBinding(text: string, location: any = null, offset: number = 0): ASTWithSource {
return createParser().parseSimpleBinding(text, location, offset);
}
function checkInterpolation(exp: string, expected?: string) {
const ast = parseInterpolation(exp) !;
if (expected == null) expected = exp;
expect(unparse(ast)).toEqual(expected);
validate(ast);
}
function checkBinding(exp: string, expected?: string) {
const ast = parseBinding(exp);
if (expected == null) expected = exp;
expect(unparse(ast)).toEqual(expected);
validate(ast);
}
function checkAction(exp: string, expected?: string) {
const ast = parseAction(exp);
if (expected == null) expected = exp;
expect(unparse(ast)).toEqual(expected);
validate(ast);
}
function expectError(ast: {errors: ParserError[]}, message: string) {
for (const error of ast.errors) {
if (error.message.indexOf(message) >= 0) {
return;
}
}
const errMsgs = ast.errors.map(err => err.message).join('\n');
throw Error(
`Expected an error containing "${message}" to be reported, but got the errors:\n` + errMsgs);
}
function expectActionError(text: string, message: string) {
expectError(validate(parseAction(text)), message);
}
function expectBindingError(text: string, message: string) {
expectError(validate(parseBinding(text)), message);
}