Same same, but different
samsam
is a collection of predicate and comparison functions useful for
identifiying the type of values and to compare values with varying degrees of
strictness.
samsam
is a general-purpose library. It works in browsers and Node. It will
define itself as an AMD module if you want it to (i.e. if there’s a define
function available).
isArguments(value)
Returns true
if value
is an arguments
object, false
otherwise.
isNegZero(value)
Returns true
if value
is -0
.
isElement(value)
Returns true
if value
is a DOM element node. Unlike
Underscore.js/lodash, this function will return false
if value
is an
element-like object, i.e. a regular object with a nodeType
property that
holds the value 1
.
isSet(value)
Returns true
if value
is a Set.
identical(x, y)
Strict equality check according to EcmaScript Harmony’s egal
.
From the Harmony wiki:
An egal function simply makes available the internal
SameValue
function from section 9.12 of the ES5 spec. If two values are egal, then they are not observably distinguishable.
identical
returns true
when ===
is true
, except for -0
and
+0
, where it returns false
. Additionally, it returns true
when
NaN
is compared to itself.
deepEqual(actual, expectation)
Deep equal comparison. Two values are “deep equal” if:
They are objects with the same set of properties, and each property
in actual
is deepEqual to the corresponding property in expectation
actual
can have symbolic properties that are missing from expectation
Match values and objects by type or or other fuzzy criteria. samsam
ships
with these built in matchers:
sinon.match.any
Matches anything.
sinon.match.defined
Requires the value to be defined.
sinon.match.truthy
Requires the value to be truthy.
sinon.match.falsy
Requires the value to be falsy.
sinon.match.bool
Requires the value to be a Boolean
sinon.match.number
Requires the value to be a Number
.
sinon.match.string
Requires the value to be a String
.
sinon.match.object
Requires the value to be an Object
.
sinon.match.func
Requires the value to be a Function
.
sinon.match.array
Requires the value to be an Array
.
sinon.match.array.deepEquals(arr)
Requires an Array
to be deep equal another one.
sinon.match.array.startsWith(arr)
Requires an Array
to start with the same values as another one.
sinon.match.array.endsWith(arr)
Requires an Array
to end with the same values as another one.
sinon.match.array.contains(arr)
Requires an Array
to contain each one of the values the given array has.
sinon.match.map
Requires the value to be a Map
.
sinon.match.map.deepEquals(map)
Requires a Map
to be deep equal another one.
sinon.match.map.contains(map)
Requires a Map
to contain each one of the items the given map has.
sinon.match.set
Requires the value to be a Set
.
sinon.match.set.deepEquals(set)
Requires a Set
to be deep equal another one.
sinon.match.set.contains(set)
Requires a Set
to contain each one of the items the given set has.
sinon.match.regexp
Requires the value to be a regular expression.
sinon.match.date
Requires the value to be a Date
object.
sinon.match.symbol
Requires the value to be a Symbol
.
sinon.match.in(array)
Requires the value to be in the array
.
sinon.match.same(ref)
Requires the value to strictly equal ref
.
sinon.match.typeOf(type)
Requires the value to be of the given type, where type
can be one of
"undefined"
,
"null"
,
"boolean"
,
"number"
,
"string"
,
"object"
,
"function"
,
"array"
,
"regexp"
,
"date"
or
"symbol"
.
sinon.match.instanceOf(type)
Requires the value to be an instance of the given type
.
sinon.match.has(property[, expectation])
Requires the value to define the given property
.
The property might be inherited via the prototype chain. If the optional expectation is given, the value of the property is deeply compared with the expectation. The expectation can be another matcher.
sinon.match.hasOwn(property[, expectation])
Same as sinon.match.has
but the property must be defined by the value itself. Inherited properties are ignored.
sinon.match.hasNested(propertyPath[, expectation])
Requires the value to define the given propertyPath
. Dot (prop.prop
) and bracket (prop[0]
) notations are supported as in Lodash.get.
The propertyPath might be inherited via the prototype chain. If the optional expectation is given, the value at the propertyPath is deeply compared with the expectation. The expectation can be another matcher.
sinon.match.hasNested("a[0].b.c");
// Where actual is something like
var actual = { a: [{ b: { c: 3 } }] };
sinon.match.hasNested("a.b.c");
// Where actual is something like
var actual = { a: { b: { c: 3 } } };
sinon.match.every(matcher)
Requires every element of an Array
, Set
or Map
, or alternatively every value of an Object
to match the given matcher
.
sinon.match.some(matcher)
Requires any element of an Array
, Set
or Map
, or alternatively any value of an Object
to match the given matcher
.
All matchers implement and
and or
. This allows to logically combine mutliple matchers. The result is a new matchers that requires both (and) or one of the matchers (or) to return true
.
var stringOrNumber = sinon.match.string.or(sinon.match.number);
var bookWithPages = sinon.match.instanceOf(Book).and(sinon.match.has("pages"));
match(object, matcher)
Creates a custom matcher to perform partial equality check. Compares object
with matcher according a wide set of rules:
In its simplest form, match
performs a case insensitive substring match.
When the matcher is a string, object
is converted to a string, and the
function returns true
if the matcher is a case-insensitive substring of
object
as a string.
samsam.match("Give me something", "Give"); //true
samsam.match("Give me something", "sumptn"); // false
samsam.match(
{
toString: function () {
return "yeah";
},
},
"Yeah!"
); // true
The last example is not symmetric. When the matcher is a string, the object
is coerced to a string - in this case using toString
. Changing the order of
the arguments would cause the matcher to be an object, in which case different
rules apply (see below).
Performs a strict (i.e. ===
) match with the object. So, only true
matches true
, and only false
matches false
.
When the matcher is a regular expression, the function will pass if
object.test(matcher)
is true
. match
is written in a generic way, so
any object with a test
method will be used as a matcher this way.
samsam.match("Give me something", /^[a-z\s]$/i); // true
samsam.match("Give me something", /[0-9]/); // false
samsam.match(
{
toString: function () {
return "yeah!";
},
},
/yeah/
); // true
samsam.match(234, /[a-z]/); // false
When the matcher is a number, the assertion will pass if object == matcher
.
samsam.match("123", 123); // true
samsam.match("Give me something", 425); // false
samsam.match(
{
toString: function () {
return "42";
},
},
42
); // true
samsam.match(234, 1234); // false
When the matcher is a function, it is called with object
as its only
argument. match
returns true
if the function returns true
. A strict
match is performed against the return value, so a boolean true
is required,
truthy is not enough.
// true
samsam.match("123", function (exp) {
return exp == "123";
});
// false
samsam.match("Give me something", function () {
return "ok";
});
// true
samsam.match(
{
toString: function () {
return "42";
},
},
function () {
return true;
}
);
// false
samsam.match(234, function () {});
As mentioned above, if an object matcher defines a test
method, match
will return true
if matcher.test(object)
returns truthy.
If the matcher does not have a test method, a recursive match is performed. If
all properties of matcher
matches corresponding properties in object
,
match
returns true
. Note that the object matcher does not care if the
number of properties in the two objects are the same - only if all properties in
the matcher recursively matches ones in object
. If supported, this object matchers
include symbolic properties
in the comparison.
// true
samsam.match("123", {
test: function (arg) {
return arg == 123;
},
});
// false
samsam.match({}, { prop: 42 });
// true
samsam.match(
{
name: "Chris",
profession: "Programmer",
},
{
name: "Chris",
}
);
// false
samsam.match(234, { name: "Chris" });
match
can be very helpful when comparing DOM elements, because it allows
you to compare several properties with one call:
var el = document.getElementById("myEl");
samsam.match(el, {
tagName: "h2",
className: "item",
innerHTML: "Howdy",
});