Erik Römmelt 5d28bc36e1 node_modules updated, buefy add to lib folder | 5 years ago | |
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lib | 5 years ago | |
README.md | 5 years ago | |
index.js | 5 years ago | |
package.json | 5 years ago |
Precondition checks for Node.js inspired by Guava’s precondition checking utilities.
npm install precond
npm test
Precond provides a set of functions to verify arguments and state correctness
It lets you rewrite constructs like the following
if (!this.isConnected) {
throw new Error('Client should be connected before calling X.');
}
into a more compact and declarative check bellow.
precond.checkState(this.isConnected, 'Client should be ...');
Note that even though the throw statement is wrapped in a function, the call stack will still start from the calling function. So the previous examples would both produce the same stack trace.
All arguments after the message will be used to format the actual error message that will be thrown.
The following precondition checks are provded:
Ensures that value is true. Throws an IllegalArgumentError
if value
is false.
Ensures that value is true. Throws an IllegalStateError
if value
is false.
Ensures that value is defined (could be null). Throws an
IllegalArgumentError
if value is undefined. Returns the value of
the value that was validated.
Ensures that value is defined and not null. Throws an
IllegalArgumentError
if value is undefined or null. Returns the value of
the value that was validated.
Ensures that value is a string or a String object. Throws an
IllegalArgumentError
if value isn’t a string. Returns the value of
the value that was validated.
Ensures that value is an array. Throws an IllegalArgumentError
if
value isn’t an array. Returns the value of the value that was
validated.
Ensures that value is a number. Throws an IllegalArgumentError
if
value isn’t a number. Returns the value of the value that was
validated.
Ensures that value is a boolean. Throws an IllegalArgumentError
if
value isn’t a boolean. Returns the value of the value that was
validated.
Ensures that value is a function. Throws an IllegalArgumentError
if
value isn’t a function. Returns the value of the value that was
validated.
Ensures that value is an object. Throws an IllegalArgumentError
if
value isn’t an object. Returns the value of the value that was
validated.
Extends Error
and is thrown to signal illegal arguments.
Extends Error
and is thrown to signal that the program or object has reached
an illegal state.
This code is free to use under the terms of the MIT license.