DRY out code, handle strict vs non-strict

src/ast/conditions.js

@@ -1,65 +1,39 @@
-function isEqualTest ( node ) {
-	return node.type === 'BinaryExpression' && ( node.operator === '===' || node.operator === '==' );
+export function isTruthy ( node ) {
+	if ( node.type === 'Literal' ) return !!node.value;
+	if ( node.type === 'ParenthesizedExpression' ) return isTruthy( node.expression );
+	if ( node.operator in operators ) return operators[ node.operator ]( node );
 }
 
-function isNotEqualTest ( node ) {
-	return node.type === 'BinaryExpression' && ( node.operator === '!==' || node.operator === '!=' );
+export function isFalsy ( node ) {
+	return not( isTruthy( node ) );
 }
 
-function nodesAreEqual ( a, b ) {
-	if ( a.type !== b.type ) return false;
-	if ( a.type === 'Literal' ) return a.value === b.value
-	if ( a.type === 'Identifier' ) return a.name === b.name && a.name !== 'NaN';
-
-	return false;
+function not ( value ) {
+	return value === undefined ? value : !value;
 }
 
-function nodesAreNotEqual ( a, b ) {
-	if ( a.type !== b.type ) return false;
-	if ( a.type === 'Literal' ) return a.value != b.value;
-	if ( a.type === 'Identifier' ) return a.name != b.name || a.name === 'NaN';
-
-	return false;
+function equals ( a, b, strict ) {
+	if ( a.type !== b.type ) return undefined;
+	if ( a.type === 'Identifier' ) return a.name === b.name && a.name !== 'NaN';
+	if ( a.type === 'Literal' ) return strict ? a.value === b.value : a.value == b.value;
 }
 
-export function isTruthy ( node ) {
-	if ( node.type === 'Literal' && node.value ) return true;
-	if ( node.type === 'ParenthesizedExpression' ) return isTruthy( node.expression );
-
-	if ( isEqualTest( node ) ) return nodesAreEqual( node.left, node.right );
-	if ( isNotEqualTest( node ) ) return nodesAreNotEqual( node.left, node.right );
+const operators = {
+	'==': x => {
+		return equals( x.left, x.right, false );
+	},
 
-	if ( node.type === 'UnaryExpression' ) {
-		if ( node.operator === '!' ) return isFalsy( node.argument );
-		return false;
-	}
+	'!=': x => not( operators['==']( x ) ),
 
-	if ( node.type === 'LogicalExpression' ) {
-		if ( node.operator === '&&' ) return isTruthy( node.left ) && isTruthy( node.right );
-		if ( node.operator === '||' ) return isTruthy( node.left ) || isTruthy( node.right );
-		return false;
-	}
+	'===': x => {
+		return equals( x.left, x.right, true );
+	},
 
-	return false;
-}
+	'!==': x => not( operators['===']( x ) ),
 
-export function isFalsy ( node ) {
-	if ( node.type === 'Literal' && !node.value ) return true;
-	if ( node.type === 'ParenthesizedExpression' ) return isFalsy( node.expression );
+	'!': x => isFalsy( x.argument ),
 
-	if ( isEqualTest( node ) ) return nodesAreNotEqual( node.left, node.right );
-	if ( isNotEqualTest( node ) ) return nodesAreEqual( node.left, node.right );
+	'&&': x => isTruthy( x.left ) && isTruthy( x.right ),
 
-	if ( node.type === 'UnaryExpression' ) {
-		if ( node.operator === '!' ) return isTruthy( node.argument );
-		return false;
-	}
-
-	if ( node.type === 'LogicalExpression' ) {
-		if ( node.operator === '&&' ) return isFalsy( node.left ) || isFalsy( node.right );
-		if ( node.operator === '||' ) return isFalsy( node.left ) && isFalsy( node.right );
-		return false;
-	}
-
-	return false;
-}
+	'||': x => isTruthy( x.left ) || isTruthy( x.right )
+};

test/function/skips-dead-branches-f/_config.js

@@ -1,7 +1,6 @@
 var assert = require( 'assert' );
 
 module.exports = {
-	solo: true,
 	description: 'skips a dead branch (f)',
 	code: function ( code ) {
 		assert.equal( code.indexOf( 'obj.foo = function' ), -1, code );

test/function/skips-dead-branches-g/_config.js

@@ -0,0 +1,8 @@
+var assert = require( 'assert' );
+
+module.exports = {
+	description: 'skips a dead branch (g)',
+	code: function ( code ) {
+		assert.equal( code.indexOf( 'obj.foo = function' ), -1, code );
+	}
+}

test/function/skips-dead-branches-g/main.js

@@ -0,0 +1,11 @@
+var obj = {};
+obj.foo = function () {
+	console.log( 'this should be excluded' );
+}
+
+function bar () {
+	console.log( 'this should be included' );
+}
+
+if ( 42 != '42' ) obj.foo();
+bar();