angular-docs-cn/modules/angular2/test/change_detection/parser/parser_spec.js

import {ddescribe, describe, it, xit, iit, expect, beforeEach} from 'angular2/test_lib';
import {BaseException, isBlank, isPresent} from 'angular2/src/facade/lang';
import {reflector} from 'angular2/src/reflection/reflection';
import {MapWrapper, ListWrapper} from 'angular2/src/facade/collection';
import {Parser} from 'angular2/src/change_detection/parser/parser';
import {Lexer} from 'angular2/src/change_detection/parser/lexer';
import {ContextWithVariableBindings} from 'angular2/src/change_detection/parser/context_with_variable_bindings';
import {Formatter, LiteralPrimitive} from 'angular2/src/change_detection/parser/ast';

class TestData {
  a;
  b;
  fnReturnValue;
  constructor(a, b, fnReturnValue) {
    this.a = a;
    this.b = b;
    this.fnReturnValue = fnReturnValue;
  }

  fn() {
    return this.fnReturnValue;
  }

  add(a, b) {
    return a + b;
  }
}

export function main() {
  function td(a = 0, b = 0, fnReturnValue = "constant") {
    return new TestData(a, b, fnReturnValue);
  }

  function createParser() {
    return new Parser(new Lexer(), reflector);
  }

  function parseAction(text, location = null) {
    return createParser().parseAction(text, location);
  }

  function parseBinding(text, location = null) {
    return createParser().parseBinding(text, location);
  }

  function parseTemplateBindings(text, location = null) {
    return createParser().parseTemplateBindings(text, location);
  }

  function parseInterpolation(text, location = null) {
    return createParser().parseInterpolation(text, location);
  }

  function expectEval(text, passedInContext = null) {
    var c = isBlank(passedInContext) ? td() : passedInContext;
    return expect(parseAction(text).eval(c));
  }

  function expectEvalError(text, passedInContext = null) {
    var c = isBlank(passedInContext) ? td() : passedInContext;
    return expect(() => parseAction(text).eval(c));
  }

  function evalAsts(asts, passedInContext = null) {
    var c = isBlank(passedInContext) ? td() : passedInContext;
    var res = [];
    for (var i=0; i<asts.length; i++) {
      ListWrapper.push(res, asts[i].eval(c));
    }
    return res;
  }

  describe("parser", () => {
    describe("parseAction", () => {
      describe("basic expressions", () => {
        it('should parse numerical expressions', () => {
          expectEval("1").toEqual(1);
        });

        it('should parse strings', () => {
          expectEval("'1'").toEqual('1');
          expectEval('"1"').toEqual('1');
        });

        it('should parse null', () => {
          expectEval("null").toBe(null);
        });

        it('should parse unary - expressions', () => {
          expectEval("-1").toEqual(-1);
          expectEval("+1").toEqual(1);
        });

        it('should parse unary ! expressions', () => {
          expectEval("!true").toEqual(!true);
          expectEval("!!true").toEqual(!!true);
        });

        it('should parse multiplicative expressions', () => {
          expectEval("3*4/2%5").toEqual(3 * 4 / 2 % 5);
        });

        it('should parse additive expressions', () => {
          expectEval("3+6-2").toEqual(3 + 6 - 2);
        });

        it('should parse relational expressions', () => {
          expectEval("2<3").toEqual(2 < 3);
          expectEval("2>3").toEqual(2 > 3);
          expectEval("2<=2").toEqual(2 <= 2);
          expectEval("2>=2").toEqual(2 >= 2);
        });

        it('should parse equality expressions', () => {
          expectEval("2==3").toEqual(2 == 3);
          expectEval("2!=3").toEqual(2 != 3);
        });

        it('should parse logicalAND expressions', () => {
          expectEval("true&&true").toEqual(true && true);
          expectEval("true&&false").toEqual(true && false);
        });

        it('should parse logicalOR expressions', () => {
          expectEval("false||true").toEqual(false || true);
          expectEval("false||false").toEqual(false || false);
        });

        it('should short-circuit AND operator', () => {
          expectEval('false && a()', td(() => {throw "BOOM"})).toBe(false);
        });

        it('should short-circuit OR operator', () => {
          expectEval('true || a()', td(() => {throw "BOOM"})).toBe(true);
        });

        it('should evaluate grouped expressions', () => {
          expectEval("(1+2)*3").toEqual((1+2)*3);
        });

        it('should parse an empty string', () => {
          expectEval('').toBeNull();
        });
      });

      describe("literals", () => {
        it('should evaluate array', () => {
          expectEval("[1][0]").toEqual(1);
          expectEval("[[1]][0][0]").toEqual(1);
          expectEval("[]").toEqual([]);
          expectEval("[].length").toEqual(0);
          expectEval("[1, 2].length").toEqual(2);
        });

        it('should evaluate map', () => {
          expectEval("{}").toEqual({});
          expectEval("{a:'b'}['a']").toEqual('b');
          expectEval("{'a':'b'}['a']").toEqual('b');
          expectEval("{\"a\":'b'}['a']").toEqual('b');
          expectEval("{\"a\":'b'}['a']").toEqual("b");
          expectEval("{}['a']").not.toBeDefined();
          expectEval("{\"a\":'b'}['invalid']").not.toBeDefined();
        });

        it('should only allow identifier, string, or keyword as map key', () => {
          expectEvalError('{(:0}').toThrowError(new RegExp('expected identifier, keyword, or string'));
          expectEvalError('{1234:0}').toThrowError(new RegExp('expected identifier, keyword, or string'));
        });
      });

      describe("member access", () => {
        it("should parse field access", () => {
          expectEval("a", td(999)).toEqual(999);
          expectEval("a.a", td(td(999))).toEqual(999);
        });

        it('should throw when accessing a field on null', () => {
          expectEvalError("a.a.a").toThrowError();
        });

        it('should only allow identifier or keyword as member names', () => {
          expectEvalError('x.(').toThrowError(new RegExp('identifier or keyword'));
          expectEvalError('x. 1234').toThrowError(new RegExp('identifier or keyword'));
          expectEvalError('x."foo"').toThrowError(new RegExp('identifier or keyword'));
        });

        it("should read a field from ContextWithVariableBindings", () => {
          var locals = new ContextWithVariableBindings(null,
              MapWrapper.createFromPairs([["key", "value"]]));
          expectEval("key", locals).toEqual("value");
        });

        it("should handle nested ContextWithVariableBindings", () => {
          var nested = new ContextWithVariableBindings(null,
              MapWrapper.createFromPairs([["key", "value"]]));
          var locals = new ContextWithVariableBindings(nested, MapWrapper.create());
          expectEval("key", locals).toEqual("value");
        });

        it("should fall back to a regular field read when ContextWithVariableBindings "+
           "does not have the requested field", () => {
          var locals = new ContextWithVariableBindings(td(999), MapWrapper.create());
          expectEval("a", locals).toEqual(999);
        });
      });

      describe("method calls", () => {
        it("should evaluate method calls", () => {
          expectEval("fn()", td(0, 0, "constant")).toEqual("constant");
          expectEval("add(1,2)").toEqual(3);
          expectEval("a.add(1,2)", td(td())).toEqual(3);
          expectEval("fn().add(1,2)", td(0, 0, td())).toEqual(3);
        });

        it('should throw when no method', () => {
          expectEvalError("blah()").toThrowError();
        });

        it('should evaluate a method from ContextWithVariableBindings', () => {
          var context = new ContextWithVariableBindings(
            td(0, 0, 'parent'),
            MapWrapper.createFromPairs([['fn', () => 'child']])
          );
          expectEval("fn()", context).toEqual('child');
        });

        it('should fall back to the parent context when ContextWithVariableBindings does not ' +
           'have the requested method', () => {
          var context = new ContextWithVariableBindings(
            td(0, 0, 'parent'),
            MapWrapper.create()
          );
          expectEval("fn()", context).toEqual('parent');
        });
      });

      describe("functional calls", () => {
        it("should evaluate function calls", () => {
          expectEval("fn()(1,2)", td(0, 0, (a, b) => a + b)).toEqual(3);
        });

        it('should throw on non-function function calls', () => {
          expectEvalError("4()").toThrowError(new RegExp('4 is not a function'));
        });

        it('should parse functions for object indices', () => {
          expectEval('a[b()]()', td([()=>6], () => 0)).toEqual(6);
        });
      });

      describe("conditional", () => {
        it('should parse ternary/conditional expressions', () => {
          expectEval("7==3+4?10:20").toEqual(10);
          expectEval("false?10:20").toEqual(20);
        });

        it('should throw on incorrect ternary operator syntax', () => {
          expectEvalError("true?1").
            toThrowError(new RegExp('Parser Error: Conditional expression true\\?1 requires all 3 expressions'));
        });
      });

      describe("assignment", () => {
        it("should support field assignments", () => {
          var context = td();
          expectEval("a=12", context).toEqual(12);
          expect(context.a).toEqual(12);
        });

        it("should support nested field assignments", () => {
          var context = td(td(td()));
          expectEval("a.a.a=123;", context).toEqual(123);
          expect(context.a.a.a).toEqual(123);
        });

        it("should support multiple assignments", () => {
          var context = td();
          expectEval("a=123; b=234", context).toEqual(234);
          expect(context.a).toEqual(123);
          expect(context.b).toEqual(234);
        });

        it("should support array updates", () => {
          var context = td([100]);
          expectEval('a[0] = 200', context).toEqual(200);
          expect(context.a[0]).toEqual(200);
        });

        it("should support map updates", () => {
          var context = td({"key" : 100});
          expectEval('a["key"] = 200', context).toEqual(200);
          expect(context.a["key"]).toEqual(200);
        });

        it("should support array/map updates", () => {
          var context = td([{"key" : 100}]);
          expectEval('a[0]["key"] = 200', context).toEqual(200);
          expect(context.a[0]["key"]).toEqual(200);
        });

        it('should allow assignment after array dereference', () => {
          var context = td([td()]);
          expectEval('a[0].a = 200', context).toEqual(200);
          expect(context.a[0].a).toEqual(200);
        });

        it('should throw on bad assignment', () => {
          expectEvalError("5=4").toThrowError(new RegExp("Expression 5 is not assignable"));
        });

        it('should reassign when no variable binding with the given name', () => {
          var context = td();
          var locals = new ContextWithVariableBindings(context, MapWrapper.create());
          expectEval('a = 200', locals).toEqual(200);
          expect(context.a).toEqual(200);
        });

        it('should throw when reassigning a variable binding', () => {
          var locals = new ContextWithVariableBindings(null, MapWrapper.createFromPairs([["key", "value"]]));
          expectEvalError('key = 200', locals).toThrowError(new RegExp("Cannot reassign a variable binding"));
        });
      });

      describe("general error handling", () => {
        it("should throw on an unexpected token", () => {
          expectEvalError("[1,2] trac")
            .toThrowError(new RegExp('Unexpected token \'trac\''));
        });

        it('should throw a reasonable error for unconsumed tokens', () => {
          expectEvalError(")").toThrowError(new RegExp("Unexpected token \\) at column 1 in \\[\\)\\]"));
        });

        it('should throw on missing expected token', () => {
          expectEvalError("a(b").toThrowError(new RegExp("Missing expected \\) at the end of the expression \\[a\\(b\\]"));
        });
      });

      it("should error when using formatters", () => {
        expectEvalError('x|blah').toThrowError(new RegExp('Cannot have a formatter'));
      });

      it('should pass exceptions', () => {
        expect(() => {
          parseAction('a()').eval(td(() => {throw new BaseException("boo to you")}));
        }).toThrowError('boo to you');
      });

      describe("multiple statements", () => {
        it("should return the last non-blank value", () => {
          expectEval("a=1;b=3;a+b").toEqual(4);
          expectEval("1;;").toEqual(1);
        });
      });

      it('should store the source in the result', () => {
        expect(parseAction('someExpr').source).toBe('someExpr');
      });

      it('should store the passed-in location', () => {
        expect(parseAction('someExpr', 'location').location).toBe('location');
      });
    });

    describe("parseBinding", () => {
      describe("formatters", () => {
        it("should parse formatters", () => {
          var exp = parseBinding("'Foo'|uppercase").ast;
          expect(exp).toBeAnInstanceOf(Formatter);
          expect(exp.name).toEqual("uppercase");
        });

        it("should parse formatters with args", () => {
          var exp = parseBinding("1|increment:2").ast;
          expect(exp).toBeAnInstanceOf(Formatter);
          expect(exp.name).toEqual("increment");
          expect(exp.args[0]).toBeAnInstanceOf(LiteralPrimitive);
        });

        it('should only allow identifier or keyword as formatter names', () => {
          expect(() => parseBinding('"Foo"|(')).toThrowError(new RegExp('identifier or keyword'));
          expect(() => parseBinding('"Foo"|1234')).toThrowError(new RegExp('identifier or keyword'));
          expect(() => parseBinding('"Foo"|"uppercase"')).toThrowError(new RegExp('identifier or keyword'));
        });

      });

      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 throw on chain expressions', () => {
        expect(() => parseBinding("1;2")).toThrowError(new RegExp("contain chained expression"));
      });

      it('should throw on assignmnt', () => {
        expect(() => parseBinding("1;2")).toThrowError(new RegExp("contain chained expression"));
      });
    });

    describe('parseTemplateBindings', () => {

      function keys(templateBindings) {
        return ListWrapper.map(templateBindings, (binding) => binding.key );
      }

      function keyValues(templateBindings) {
        return ListWrapper.map(templateBindings, (binding) => {
          if (binding.keyIsVar) {
            return '#' + binding.key + (isBlank(binding.name) ? '' : '=' + binding.name);
          } else {
            return binding.key +  (isBlank(binding.expression) ? '' : `=${binding.expression}`)
          }
        });
      }

      function exprSources(templateBindings) {
        return ListWrapper.map(templateBindings,
          (binding) => isPresent(binding.expression) ? binding.expression.source : null );
      }

      function exprAsts(templateBindings) {
        return ListWrapper.map(templateBindings,
          (binding) => isPresent(binding.expression) ? binding.expression : null );
      }

      it('should parse an empty string', () => {
        var bindings = parseTemplateBindings('');
        expect(bindings).toEqual([]);
      });

      it('should parse a string without a value', () => {
        var bindings = parseTemplateBindings('a');
        expect(keys(bindings)).toEqual(['a']);
      });

      it('should only allow identifier, string, or keyword including dashes as keys', () => {
        var bindings = parseTemplateBindings("a:'b'");
        expect(keys(bindings)).toEqual(['a']);

        bindings = parseTemplateBindings("'a':'b'");
        expect(keys(bindings)).toEqual(['a']);

        bindings = parseTemplateBindings("\"a\":'b'");
        expect(keys(bindings)).toEqual(['a']);

        bindings = parseTemplateBindings("a-b:'c'");
        expect(keys(bindings)).toEqual(['a-b']);

        expect( () => {
          parseTemplateBindings('(:0');
        }).toThrowError(new RegExp('expected identifier, keyword, or string'));

        expect( () => {
          parseTemplateBindings('1234:0');
        }).toThrowError(new RegExp('expected identifier, keyword, or string'));
      });

      it('should detect expressions as value', () => {
        var bindings = parseTemplateBindings("a:b");
        expect(exprSources(bindings)).toEqual(['b']);
        expect(evalAsts(exprAsts(bindings), td(0, 23))).toEqual([23]);

        bindings = parseTemplateBindings("a:1+1");
        expect(exprSources(bindings)).toEqual(['1+1']);
        expect(evalAsts(exprAsts(bindings))).toEqual([2]);
      });

      it('should detect names as value', () => {
        var bindings = parseTemplateBindings("a:#b");
        expect(keyValues(bindings)).toEqual(['a', '#b']);
      });

      it('should allow space and colon as separators', () => {
        var bindings = parseTemplateBindings("a:b");
        expect(keys(bindings)).toEqual(['a']);
        expect(exprSources(bindings)).toEqual(['b']);

        bindings = parseTemplateBindings("a b");
        expect(keys(bindings)).toEqual(['a']);
        expect(exprSources(bindings)).toEqual(['b']);
      });

      it('should allow multiple pairs', () => {
        var bindings = parseTemplateBindings("a 1 b 2");
        expect(keys(bindings)).toEqual(['a', 'b']);
        expect(exprSources(bindings)).toEqual(['1 ', '2']);
      });

      it('should store the sources in the result', () => {
        var 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', () => {
        var bindings = parseTemplateBindings("a 1,b 2", 'location');
        expect(bindings[0].expression.location).toEqual('location');
      });

      it('should support var/# notation', () => {
        var bindings = parseTemplateBindings("var i");
        expect(keyValues(bindings)).toEqual(['#i']);

        bindings = parseTemplateBindings("#i");
        expect(keyValues(bindings)).toEqual(['#i']);

        bindings = parseTemplateBindings("var i-a = k-a");
        expect(keyValues(bindings)).toEqual(['#i-a=k-a']);

        bindings = parseTemplateBindings("keyword var item; var i = k");
        expect(keyValues(bindings)).toEqual(['keyword', '#item=\$implicit', '#i=k']);

        bindings = parseTemplateBindings("keyword: #item; #i = k");
        expect(keyValues(bindings)).toEqual(['keyword', '#item=\$implicit', '#i=k']);

        bindings = parseTemplateBindings("directive: var item in expr; var a = b", 'location');
        expect(keyValues(bindings)).toEqual(['directive', '#item=\$implicit', 'in=expr in location', '#a=b']);
      });
    });

    describe('parseInterpolation', () => {
      it('should return null if no interpolation', () => {
        expect(parseInterpolation('nothing')).toBe(null);
      });

      it('should parse no prefix/suffix interpolation', () => {
        var ast = parseInterpolation('{{a}}').ast;
        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', () => {
        var ast = parseInterpolation('before{{a}}middle{{b}}after').ast;
        expect(ast.strings).toEqual(['before', 'middle', 'after']);
        expect(ast.expressions.length).toEqual(2);
        expect(ast.expressions[0].name).toEqual('a');
        expect(ast.expressions[1].name).toEqual('b');
      });
    });

    describe('wrapLiteralPrimitive', () => {
      it('should wrap a literal primitive', () => {
        expect(createParser().wrapLiteralPrimitive("foo", null).eval(null)).toEqual("foo");
      });
    });
  });
}