LibJS: Function declarations in if statement clauses
https://tc39.es/ecma262/#sec-functiondeclarations-in-ifstatement-statement-clauses
B.3.4 FunctionDeclarations in IfStatement Statement Clauses
The following augments the IfStatement production in 13.6:
    IfStatement[Yield, Await, Return] :
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else Statement[?Yield, ?Await, ?Return]
        if ( Expression[+In, ?Yield, ?Await] ) Statement[?Yield, ?Await, ?Return] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default]
This production only applies when parsing non-strict code. Code matching
this production is processed as if each matching occurrence of
FunctionDeclaration[?Yield, ?Await, ~Default] was the sole
StatementListItem of a BlockStatement occupying that position in the
source code. The semantics of such a synthetic BlockStatement includes
the web legacy compatibility semantics specified in B.3.3.
											
										 
										
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								describe("function declarations in if statement clauses", () => {
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								    test("if clause", () => {
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								        if (true) function foo() {}
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								        if (false) function bar() {}
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								        expect(typeof foo).toBe("function");
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								        expect(typeof bar).toBe("undefined");
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												LibJS: Function declarations in if statement clauses
https://tc39.es/ecma262/#sec-functiondeclarations-in-ifstatement-statement-clauses
B.3.4 FunctionDeclarations in IfStatement Statement Clauses
The following augments the IfStatement production in 13.6:
    IfStatement[Yield, Await, Return] :
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else Statement[?Yield, ?Await, ?Return]
        if ( Expression[+In, ?Yield, ?Await] ) Statement[?Yield, ?Await, ?Return] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default]
This production only applies when parsing non-strict code. Code matching
this production is processed as if each matching occurrence of
FunctionDeclaration[?Yield, ?Await, ~Default] was the sole
StatementListItem of a BlockStatement occupying that position in the
source code. The semantics of such a synthetic BlockStatement includes
the web legacy compatibility semantics specified in B.3.3.
											
										 
										
											2020-10-31 13:37:09 +00:00
										 
									 
								 
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								    });
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								    test("else clause", () => {
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								        if (false);
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								        else function foo() {}
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								        if (true);
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								        else function bar() {}
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											2021-05-13 23:58:45 +01:00
										 
									 
								 
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								        expect(typeof foo).toBe("function");
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								        expect(typeof bar).toBe("undefined");
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												LibJS: Function declarations in if statement clauses
https://tc39.es/ecma262/#sec-functiondeclarations-in-ifstatement-statement-clauses
B.3.4 FunctionDeclarations in IfStatement Statement Clauses
The following augments the IfStatement production in 13.6:
    IfStatement[Yield, Await, Return] :
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else Statement[?Yield, ?Await, ?Return]
        if ( Expression[+In, ?Yield, ?Await] ) Statement[?Yield, ?Await, ?Return] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default]
This production only applies when parsing non-strict code. Code matching
this production is processed as if each matching occurrence of
FunctionDeclaration[?Yield, ?Await, ~Default] was the sole
StatementListItem of a BlockStatement occupying that position in the
source code. The semantics of such a synthetic BlockStatement includes
the web legacy compatibility semantics specified in B.3.3.
											
										 
										
											2020-10-31 13:37:09 +00:00
										 
									 
								 
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								    });
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								    test("if and else clause", () => {
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								        if (true) function foo() {}
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								        else function bar() {}
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											2021-05-13 23:58:45 +01:00
										 
									 
								 
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								        expect(typeof foo).toBe("function");
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								        expect(typeof bar).toBe("undefined");
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												LibJS: Function declarations in if statement clauses
https://tc39.es/ecma262/#sec-functiondeclarations-in-ifstatement-statement-clauses
B.3.4 FunctionDeclarations in IfStatement Statement Clauses
The following augments the IfStatement production in 13.6:
    IfStatement[Yield, Await, Return] :
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else Statement[?Yield, ?Await, ?Return]
        if ( Expression[+In, ?Yield, ?Await] ) Statement[?Yield, ?Await, ?Return] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default] else FunctionDeclaration[?Yield, ?Await, ~Default]
        if ( Expression[+In, ?Yield, ?Await] ) FunctionDeclaration[?Yield, ?Await, ~Default]
This production only applies when parsing non-strict code. Code matching
this production is processed as if each matching occurrence of
FunctionDeclaration[?Yield, ?Await, ~Default] was the sole
StatementListItem of a BlockStatement occupying that position in the
source code. The semantics of such a synthetic BlockStatement includes
the web legacy compatibility semantics specified in B.3.3.
											
										 
										
											2020-10-31 13:37:09 +00:00
										 
									 
								 
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								    });
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								    test("syntax error in strict mode", () => {
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								        expect(`
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								            "use strict";
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								            if (true) function foo() {}
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								        `).not.toEval();
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								        expect(`
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								            "use strict";
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								            if (false);
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								            else function foo() {}
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								        `).not.toEval();
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								        expect(`
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								            "use strict";
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								            if (false) function foo() {}
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								            else function bar() {}
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								        `).not.toEval();
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								    });
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								});
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