deep-compare-by/README.md

Deep compare with a function

Deep compare with a function
```js
const compare = require("deep-compare-by");
const cmp = compare((a, b) => (
    (typeof a === "function") &&
    (typeof b === "function") &&
    (a.toString() == b.toString())
));
cmp({
    a:1,
    b:{
        c:2,
        d:()=>4
    }
},{
    a:1,
    b:{
        c:2,
        d:()=>4
    }
}); // returns true
```
more examples can be found in test.js
## Curryable
```js
compare(test)(lhs)(rhs)
compare(test,lhs)(rhs)
compare(test)(lhs,rhs)
compare(test,lhs,rhs)
```
```js
const cmp = compare(null,{a:1});
cmp({a:0}); // false
cmp({a:1}); // true
cmp({a:1,b:2}); // false
```
# Arguments
```js
compare(compareFunctions,lhs,rhs);
```
## Compare Functions
This set of functions will be run to compare each object or value in the passed items, if any of the functions return true the corresponding items will be considered equivalent, there is an implicit test `(a,b)=>a===b` which exists unless using noDefault
```js
compare(null); // same as compare []
compare((a,b)=>a<b); // same as [(a,b)=>a<b]
const cmp = compare(null);
const cmpt = compare([
    (a, b) => (typeof a === typeof b),
    (a, b) => (a === 9)
]);
cmp(1, 2); // false
cmpt(1, 2); // true
cmp(9, "8"); // false
cmpt(8, "8"); // false
cmpt(9, "8"); // true
```
## Modifiers
Modifiers call a modified version of the function
### noDefault
Call without implicit test `(a,b)=>a===b`

```js
const cmp = compare.noDefault((a, b) => b === 3);
cmp({ a: 1 }, { a: 1 }); // false
cmp({ a: 1 }, { a: 3 }); // true
const cmp2 = compare((a, b) => b === 3, { a: 1 });
cmp2.noDefault({ a: 1 }); // false
cmp2.noDefault({ a: 3 }); // true
```

### failPath

Instead of false, it returns the key path to the point where the compare failed. If it succeeds, return true;

```js
const val1 = {
    a: { b: { c: 2 } },
    d: 3,
    e: { f: 4 },
};
const val2 = {
    a: { b: { c: 3 } },
    d: 3,
    e: { f: 4 },
};
compare(null).failPath(val1, val2); // ['a', 'b', 'c']
compare(null)(val1).failPath(val2); // ['a', 'b', 'c']
```

## Content
Return data about the function
### tests
Returns array of tests currently curried in
```js
const cmp = compare(null);
cmp.tests(); // []
const cmpt = compare((a, b) => (typeof a === typeof b));
cmpt.tests(); // [(a, b) => (typeof a === typeof b)]
```
### lhs
Returns lhs value currently curried in, otherwise undefined
```js
compare(null,5).lhs(); // 5
```