Namespace goog.asserts

code »

Classes

goog.asserts.AssertionError
Error object for failed assertions.
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Global Functions

The default error handler.

Parameters
e: !goog.asserts.AssertionError
The exception to be handled.
code »<T> goog.asserts.assert ( condition, opt_message, var_args )T

Checks if the condition evaluates to true if goog.asserts.ENABLE_ASSERTS is true.

Parameters
condition: T
The condition to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value of the condition.
Throws
goog.asserts.AssertionError
When the condition evaluates to false.
code »goog.asserts.assertArray ( value, opt_message, var_args )!Array

Checks if the value is an Array if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a non-null array.
Throws
goog.asserts.AssertionError
When the value is not an array.
code »goog.asserts.assertBoolean ( value, opt_message, var_args )boolean

Checks if the value is a boolean if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a boolean when asserts are enabled.
Throws
goog.asserts.AssertionError
When the value is not a boolean.
code »goog.asserts.assertElement ( value, opt_message, var_args )!Element

Checks if the value is a DOM Element if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, likely to be a DOM Element when asserts are enabled.
Throws
goog.asserts.AssertionError
When the value is not a boolean.
code »goog.asserts.assertFunction ( value, opt_message, var_args )!Function

Checks if the value is a function if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a function when asserts enabled.
Throws
goog.asserts.AssertionError
When the value is not a function.
code »<T> goog.asserts.assertInstanceof ( value, type, opt_message, var_args )!T

Checks if the value is an instance of the user-defined type if goog.asserts.ENABLE_ASSERTS is true. The compiler may tighten the type returned by this function.

Parameters
value: *
The value to check.
type: function(new: T, ...)
A user-defined constructor.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Throws
goog.asserts.AssertionError
When the value is not an instance of type.
code »goog.asserts.assertNumber ( value, opt_message, var_args )number

Checks if the value is a number if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a number when asserts enabled.
Throws
goog.asserts.AssertionError
When the value is not a number.
code »goog.asserts.assertObject ( value, opt_message, var_args )!Object

Checks if the value is an Object if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a non-null object.
Throws
goog.asserts.AssertionError
When the value is not an object.

Checks that no enumerable keys are present in Object.prototype. Such keys would break most code that use for (var ... in ...) loops.

code »goog.asserts.assertString ( value, opt_message, var_args )string

Checks if the value is a string if goog.asserts.ENABLE_ASSERTS is true.

Parameters
value: *
The value to check.
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Returns
The value, guaranteed to be a string when asserts enabled.
Throws
goog.asserts.AssertionError
When the value is not a string.
code »goog.asserts.doAssertFailure_ ( defaultMessage, defaultArgs, givenMessage, givenArgs )

Throws an exception with the given message and "Assertion failed" prefixed onto it.

Parameters
defaultMessage: string
The message to use if givenMessage is empty.
defaultArgs: Array
The substitution arguments for defaultMessage.
givenMessage: (string|undefined)
Message supplied by the caller.
givenArgs: Array
The substitution arguments for givenMessage.
Throws
goog.asserts.AssertionError
When the value is not a number.

The handler responsible for throwing or logging assertion errors.

code »goog.asserts.fail ( opt_message, var_args )

Fails if goog.asserts.ENABLE_ASSERTS is true. This function is useful in case when we want to add a check in the unreachable area like switch-case statement:

  switch(type) {
    case FOO: doSomething(); break;
    case BAR: doSomethingElse(); break;
    default: goog.assert.fail('Unrecognized type: ' + type);
      // We have only 2 types - "default:" section is unreachable code.
  }
 
Parameters
opt_message: string=
Error message in case of failure.
var_args: ...*
The items to substitute into the failure message.
Throws
goog.asserts.AssertionError
Failure.

Sets a custom error handler that can be used to customize the behavior of assertion failures, for example by turning all assertion failures into log messages.

Parameters
errorHandler

Compiler Constants