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[#25] [#25] Began moving MemberBuilder validation rules into MemberBuilderValidator (moved method rules)

closure/master
Mike Gerwitz 2011-10-22 01:00:17 -04:00
parent e6830b741f
commit f9b951ddb2
3 changed files with 547 additions and 124 deletions

View File

@ -30,7 +30,9 @@
var util = require( __dirname + '/util' ), var util = require( __dirname + '/util' ),
Warning = require( __dirname + '/warn' ).Warning, Warning = require( __dirname + '/warn' ).Warning,
visibility = [ 'public', 'protected', 'private' ] visibility = [ 'public', 'protected', 'private' ],
validate = require( __dirname + '/MemberBuilderValidator' )()
; ;
@ -47,6 +49,9 @@ module.exports = function MemberBuilder( wrap_method, wrap_override )
this._wrapMethod = wrap_method; this._wrapMethod = wrap_method;
this._wrapOverride = wrap_override; this._wrapOverride = wrap_override;
// XXX: temporarily tightly coupled
this._validate = validate;
}; };
@ -108,7 +113,9 @@ exports.buildMethod = function(
// ensure that the declaration is valid (keywords make sense, argument // ensure that the declaration is valid (keywords make sense, argument
// length, etc) // length, etc)
this._validateMethod( keywords, prev_data, prev_keywords, value, name ); this._validate.validateMethod(
name, value, keywords, prev_data, prev_keywords
);
// we might be overriding an existing method // we might be overriding an existing method
if ( prev ) if ( prev )
@ -147,128 +154,6 @@ exports.buildMethod = function(
}; };
/**
* Validates a method declaration, ensuring that keywords are valid, overrides
* make sense, etc.
*
* @param {Object.<string,boolean>} keywords parsed keywords
*
* @param {Object} prev_data data of member being overridden
* @param {Object} prev_keywords keywords of member being overridden
* @param {*} value property value
* @param {string} name property name
*/
exports._validateMethod = function(
keywords, prev_data, prev_keywords, value, name )
{
var prev = ( prev_data ) ? prev_data.member : null;
if ( keywords[ 'abstract' ] )
{
// do not permit private abstract methods (doesn't make sense, since
// they cannot be inherited/overridden)
if ( keywords[ 'private' ] )
{
throw TypeError(
"Method '" + name + "' cannot be both private and abstract"
);
}
}
// const doesn't make sense for methods; they're always immutable
if ( keywords[ 'const' ] )
{
throw TypeError(
"Cannot declare method '" + name + "' as constant; keyword is " +
"redundant"
);
}
// virtual static does not make sense, as static methods cannot be
// overridden
if ( keywords[ 'virtual' ] && ( keywords[ 'static' ] ) )
{
throw TypeError(
"Cannot declare static method '" + name + "' as virtual"
);
}
// do not allow overriding getters/setters
if ( prev_data && ( prev_data.get || prev_data.set ) )
{
throw TypeError(
"Cannot override getter/setter '" + name + "' with method"
);
}
// search for any previous instances of this member
if ( prev )
{
// disallow overriding properties with methods
if ( !( prev instanceof Function ) )
{
throw TypeError(
"Cannot override property '" + name + "' with method"
);
}
// disallow overriding non-virtual methods
if ( keywords[ 'override' ] && !( prev_keywords[ 'virtual' ] ) )
{
throw TypeError(
"Cannot override non-virtual method '" + name + "'"
);
}
// do not allow overriding concrete methods with abstract
if ( keywords[ 'abstract' ] && !( prev_keywords[ 'abstract' ] ) )
{
throw TypeError(
"Cannot override concrete method '" + name + "' with " +
"abstract method"
);
}
// ensure parameter list is at least the length of its supertype
if ( ( value.__length || value.length )
< ( prev.__length || prev.length )
)
{
throw TypeError(
"Declaration of method '" + name + "' must be compatiable " +
"with that of its supertype"
);
}
// do not permit visibility deescalation
if ( this._getVisibilityValue( prev_keywords ) <
this._getVisibilityValue( keywords )
)
{
throw TypeError(
"Cannot de-escalate visibility of method '" + name + "'"
);
}
// if redefining a method that has already been implemented in the
// supertype, the default behavior is to "hide" the method of the
// supertype, unless otherwise specified
//
// IMPORTANT: do this last, to ensure we throw errors before warnings
if ( !( keywords[ 'new' ] || keywords[ 'override' ] ) )
{
if ( !( prev_keywords[ 'abstract' ] ) )
{
throw Warning( Error(
"Hiding method '" + name + "'; " +
"use 'new' if intended, or 'override' to override instead"
) );
}
}
}
}
/** /**
* Copies a property to the appropriate member prototype, depending on * Copies a property to the appropriate member prototype, depending on
* visibility, and assigns necessary metadata from keywords * visibility, and assigns necessary metadata from keywords

View File

@ -0,0 +1,191 @@
/**
* Validation rules for members
*
* Copyright (C) 2010 Mike Gerwitz
*
* This file is part of ease.js.
*
* ease.js is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @author Mike Gerwitz
* @package core
*/
// XXX: remove dependency
var Warning = require( __dirname + '/warn' ).Warning;
module.exports = exports = function MemberBuilderValidator()
{
// permit omitting 'new' keyword
if ( !( this instanceof module.exports ) )
{
return new module.exports();
}
};
/**
* Validates a method declaration, ensuring that keywords are valid, overrides
* make sense, etc.
*
* Throws exception on validation failure
*
* @param {string} name method name
* @param {*} value method value
*
* @param {Object.<string,boolean>} keywords parsed keywords
*
* @param {Object} prev_data data of member being overridden
* @param {Object} prev_keywords keywords of member being overridden
*
* @return {undefined}
*/
exports.prototype.validateMethod = function(
name, value, keywords, prev_data, prev_keywords
)
{
var prev = ( prev_data ) ? prev_data.member : null;
if ( keywords[ 'abstract' ] )
{
// do not permit private abstract methods (doesn't make sense, since
// they cannot be inherited/overridden)
if ( keywords[ 'private' ] )
{
throw TypeError(
"Method '" + name + "' cannot be both private and abstract"
);
}
}
// const doesn't make sense for methods; they're always immutable
if ( keywords[ 'const' ] )
{
throw TypeError(
"Cannot declare method '" + name + "' as constant; keyword is " +
"redundant"
);
}
// virtual static does not make sense, as static methods cannot be
// overridden
if ( keywords[ 'virtual' ] && ( keywords[ 'static' ] ) )
{
throw TypeError(
"Cannot declare static method '" + name + "' as virtual"
);
}
// do not allow overriding getters/setters
if ( prev_data && ( prev_data.get || prev_data.set ) )
{
throw TypeError(
"Cannot override getter/setter '" + name + "' with method"
);
}
// search for any previous instances of this member
if ( prev )
{
// disallow overriding properties with methods
if ( !( typeof prev === 'function' ) )
{
throw TypeError(
"Cannot override property '" + name + "' with method"
);
}
// disallow overriding non-virtual methods
if ( keywords[ 'override' ] && !( prev_keywords[ 'virtual' ] ) )
{
throw TypeError(
"Cannot override non-virtual method '" + name + "'"
);
}
// do not allow overriding concrete methods with abstract
if ( keywords[ 'abstract' ] && !( prev_keywords[ 'abstract' ] ) )
{
throw TypeError(
"Cannot override concrete method '" + name + "' with " +
"abstract method"
);
}
// ensure parameter list is at least the length of its supertype
if ( ( value.__length || value.length )
< ( prev.__length || prev.length )
)
{
throw TypeError(
"Declaration of method '" + name + "' must be compatible " +
"with that of its supertype"
);
}
// do not permit visibility deescalation
if ( this._getVisibilityValue( prev_keywords ) <
this._getVisibilityValue( keywords )
)
{
throw TypeError(
"Cannot de-escalate visibility of method '" + name + "'"
);
}
// if redefining a method that has already been implemented in the
// supertype, the default behavior is to "hide" the method of the
// supertype, unless otherwise specified
//
// IMPORTANT: do this last, to ensure we throw errors before warnings
if ( !( keywords[ 'new' ] || keywords[ 'override' ] ) )
{
if ( !( prev_keywords[ 'abstract' ] ) )
{
throw Warning( Error(
"Hiding method '" + name + "'; " +
"use 'new' if intended, or 'override' to override instead"
) );
}
}
}
};
/**
* Return the visibility level as a numeric value, where 0 is public and 2 is
* private
*
* @param {Object} keywords keywords to scan for visibility level
*
* @return {number} visibility level as a numeric value
*/
exports.prototype._getVisibilityValue = function( keywords )
{
if ( keywords[ 'protected' ] )
{
return 1;
}
else if ( keywords[ 'private' ] )
{
return 2;
}
else
{
// default is public
return 0;
}
}

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@ -0,0 +1,347 @@
/**
* Tests member builder validation rules
*
* Copyright (C) 2010 Mike Gerwitz
*
* This file is part of ease.js.
*
* ease.js is free software: you can redistribute it and/or modify it under the
* terms of the GNU Lesser General Public License as published by the Free
* Software Foundation, either version 3 of the License, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser General Public License
* for more details.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*
* @author Mike Gerwitz
* @package test
*/
require( 'common' ).testCase(
{
setUp: function()
{
var _self = this;
this.sut = this.require( 'MemberBuilderValidator' )();
/**
* Tests to ensure that a method with the given keywords fails
* validation with an error message partially matching the provided
* identifier
*/
this.quickKeywordMethodTest = function( keywords, identifier )
{
var keyword_obj = {},
name = 'fooBar';
// convert our convenient array into a keyword obj
for ( var i = 0, len = keywords.length; i < len; i++ )
{
keyword_obj[ keywords[ i ] ] = true;
}
_self.quickFailureTest( name, identifier, function()
{
_self.sut.validateMethod(
name, function() {}, keyword_obj, {}, {}
);
} );
};
this.quickFailureTest = function( name, identifier, action )
{
_self.incAssertCount();
try
{
action();
}
catch ( e )
{
// using the identifier, ensure the error string makes sense
_self.assertOk( ( e.message.search( identifier ) !== -1 ),
"Incorrect error; expected identifier '" + identifier +
"', but received: " + e.message
);
// to aid in debugging, the error message should contain the
// name of the method
_self.assertOk( ( e.message.search( name ) !== -1 ),
'Error message should contain method name'
);
return;
}
_self.fail( "Expected failure" );
};
this.quickVisChangeTest = function( start, override, failtest )
{
var name = 'foo',
startobj = { 'virtual': true },
overrideobj = { 'override': true }
;
startobj[ start ] = true;
overrideobj[ override ] = true;
var testfun = function()
{
_self.sut.validateMethod(
name,
function() {},
overrideobj,
{ member: function() {} },
startobj
);
};
if ( failtest )
{
this.quickFailureTest( name, 'de-escalate', testfun );
}
else
{
_self.assertDoesNotThrow( testfun, Error );
}
};
},
/**
* Private, abstract methods do not make sense. Private methods cannot be
* overridden.
*/
'Method cannot be both private and abstract': function()
{
this.quickKeywordMethodTest( [ 'private', 'abstract' ],
'private and abstract'
);
},
/**
* Methods (in terms of a class) are always immutable. As such, `const'
* would be redundant.
*/
'Methods cannot be declared const': function()
{
this.quickKeywordMethodTest( [ 'const' ], 'const' );
},
/**
* Virtual static methods do not make sense because static methods can only
* be hidden, not overridden.
*/
'Method cannot be both virtual and static': function()
{
this.quickKeywordMethodTest( [ 'virtual', 'static' ], 'static' );
},
/**
* Getters/setters are treated as properties and should not be able to be
* overridden with methods.
*/
'Cannot override getter/setter with method': function()
{
var name = 'foo',
_self = this;
// test getter
this.quickFailureTest( name, 'getter/setter', function()
{
_self.sut.validateMethod(
name, function() {}, {},
{ get: function() {} },
{}
);
} );
// test setter
this.quickFailureTest( name, 'getter/setter', function()
{
_self.sut.validateMethod(
name, function() {}, {},
{ set: function() {} },
{}
);
} );
},
/**
* Although a function can certainly be assigned to a property, we cannot
* allow /declaring/ a method in place of a parent property, as that alters
* the interface.
*/
'Cannot override property with method': function()
{
var name = 'foo',
_self = this;
this.quickFailureTest( name, 'property', function()
{
// attempt to override a property
_self.sut.validateMethod(
name, function() {}, {},
{ member: 'immaprop' },
{}
);
} );
},
/**
* The `virtual' keyword denotes a method that may be overridden. Without
* it, we should not allow overriding.
*/
'Cannot override non-virtual methods': function()
{
var name = 'foo',
_self = this;
this.quickFailureTest( name, 'non-virtual', function()
{
// override provided, but not 'virtual'
_self.sut.validateMethod(
name,
function() {},
{ override: true },
{ member: function() {} },
{}
);
} );
},
/**
* Abstract methods act as a sort of placeholder, requiring an
* implementation. Once an implementation has been defined, it does not make
* sense (in the context of inheritance) to remove it entirely by reverting
* back to an abstract method.
*/
'Cannot override concrete method with abstract method': function()
{
var name = 'foo',
_self = this;
this.quickFailureTest( name, 'concrete', function()
{
// attempting to override concrete (non-abstract) method
_self.sut.validateMethod(
name,
function() {},
{ 'abstract': true },
{ member: function() {} },
{}
);
} );
},
/**
* The parameter list is part of the class interface. Changing the length
* will make the interface incompatible with that of its parent and make
* polymorphism difficult. However, since all parameters in JS are
* technically optional, we can permit extending the parameter list (which
* itself has its dangers since the compiler cannot detect type errors).
*/
'Override parameter list must match or exceed parent length': function()
{
var name = 'foo',
_self = this;
// check with parent with three params
this.quickFailureTest( name, 'compatible', function()
{
_self.sut.validateMethod(
name,
function() {},
{ 'override': true },
{ member: function( a, b, c ) {} },
{ 'virtual': true }
);
} );
// also check with __length property (XXX: testing too closely to the
// implementation; provide abstraction)
this.quickFailureTest( name, 'compatible', function()
{
var parent_method = function() {};
parent_method.__length = 3;
_self.sut.validateMethod(
name,
function() {},
{ 'override': true },
{ member: parent_method },
{ 'virtual': true }
);
} );
// finally, check __length of override will actually work (no error)
this.assertDoesNotThrow( function()
{
var method = function() {};
method.__length = 3;
_self.sut.validateMethod(
name,
method,
{ 'override': true },
{ member: function( a, b, c ) {} },
{ 'virtual': true }
);
}, Error );
},
/**
* One should not be able to, for example, declare a private method it had
* previously been declared protected, or declare it as protected if it has
* previously been declared public. Again - the reason being interface
* consistency. Otherwise the concept of polymorphism doesn't work.
*/
'Methods do not support visibiliy de-escalation': function()
{
this.quickVisChangeTest( 'public', 'protected', true );
this.quickVisChangeTest( 'protected', 'private', true );
},
/**
* To ensure we don't have a bug in our validation, let's also test the
* reverse - ensure that we support escalation and staying at the same
* level.
*/
'Methods support visibility escalation or equality': function()
{
var tests = [
[ 'private', 'protected' ],
[ 'protected', 'public' ],
[ 'public', 'public' ],
[ 'protected', 'protected' ],
[ 'private', 'private' ]
];
for ( var i = 0, len = tests.length; i < len; i++ )
{
var cur = tests[ i ];
this.quickVisChangeTest( cur[ 0 ], cur[ 1 ], false );
}
},
} );