arraydiff/test.js at master · derbyjs/arraydiff · GitHub

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varexpect=require('expect.js');
vararrayDiff=require('./index');
varInsertDiff=arrayDiff.InsertDiff;
varRemoveDiff=arrayDiff.RemoveDiff;
varMoveDiff=arrayDiff.MoveDiff;

functioninsert(array,index,values){
array.splice.apply(array,[index,0].concat(values));
}

functionremove(array,index,howMany){
returnarray.splice(index,howMany);
}

functionmove(array,from,to,howMany){
varvalues=remove(array,from,howMany);
insert(array,to,values);
}

functionapplyDiff(before,diff){
varout=before.slice();
for(vari=0;i<diff.length;i++){
varitem=diff[i];
// console.log 'applying:', out, item
if(iteminstanceofInsertDiff){
insert(out,item.index,item.values);
}elseif(iteminstanceofRemoveDiff){
remove(out,item.index,item.howMany);
}elseif(iteminstanceofMoveDiff){
move(out,item.from,item.to,item.howMany);
}
}
returnout;
}

functionrandomWhole(max){
returnMath.floor(Math.random()*(max+1));
}

functionrandomArray(maxLength,maxValues){
if(maxLength==null)maxLength=20;
if(maxValues==null)maxValues=maxLength;
varresults=[];
for(vari=randomWhole(maxLength);i--;){
results.push(randomWhole(maxValues));
}
returnresults;
}

functiontestDiff(before,after,equalFn){
// console.log()
// console.log 'before =', before
// console.log 'after =', after
vardiff=arrayDiff(before,after,equalFn);
varexpected=applyDiff(before,diff);
expect(expected).to.eql(after);
}

describe('arrayDiff',function(){

it('diffs empty arrays',function(){
testDiff([],[]);
testDiff([],[0,1,2]);
testDiff([0,1,2],[]);
});

it('supports custom equality comparisons',function(){
varbefore=[{id: 1},{id: 2}];
varafter=[{id: 1}];
testDiff(before,after,function(a,b){
returna.id===b.id;
});
});

it('diffs randomly rearranged arrays of numbers',function(){
functionrandomSort(){
returnMath.random()-0.5;
}
for(vari=1000;i--;){
// before = [0,1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]
varbefore=randomArray(50);
varafter=before.slice().sort(randomSort);
testDiff(before,after);
}
});

it('diffs random arrays of numbers',function(){
for(vari=1000;i--;){
varbefore=randomArray(50,20);
varafter=randomArray(50,20);
testDiff(before,after);
}
});

});