Check if a context has a function property, optionally with specified number of formal parameters... |
Syntax
hasFunction( context, key[, paramCount] ); |
Parameters
| Parameter | Type | Mandatory | Notes | API Version |
|---|---|---|---|---|
| context | Variant |  | The object to which the function is attached. | 1.5 |
| key | String | | The name of the property that should be a function. | 1.5 |
| paramCount | Number |  | The number of formally defined parameters the function should have. Default: Don't check parameter count. Note: JS API functions don't specify any formal parameters | 1.5 |
Return Values
| Value | Type | Notes | API Version |
|---|---|---|---|
| <error> | Error | Most likely the parameters are wrong. | 1.0 |
true | Boolean | The assertion passed. | 1.0 |
false | Boolean | The assertion failed. | 1.0 |
Notes
The assertion is performed in three stages:
- Assert that the property 'key' exists
- Assert that the value of the property is a function
- If paramCount specified, assert the number of formal parameters matches paramCount
The message added to the test results indicates indicates which stage hasFunction( ) had got to when the assertion passed or failed.
Example
// let's say we're testing this...
var foo = {
bar: function(a, b, c) {},
chimp: "not a function"
}
Test("foo.bar() defined", Test.ANY( ), function() {
hasFunction( foo, "meh" ); // fails - no property called "meh"
hasFunction( foo, "bar" ); // passes
hasFunction( foo, "chimp" ); // fails - chimp is not a function
hasFunction( foo, "bar", 3 ); // passes
hasFunction( foo, "bar", 4 ); // fails - bar() has 3 formal params
}); |