View source for Module:CallAssert/doc

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This [[Help:Lua metamodules|metamodule]] provides function '''callAssert''', which simplifies error checking by throwing an error if a given function returns nil or false. This is similar to the built-in function [[mw:LUAREF#assert|assert]], but unlike it, callAssert itself calls the function, whose return value is to be checked. This allows it to include the function name and argument values in the error message.

== Usage ==

 local callAssert = require('Module:CallAssert')
 local result1, result2, etc = '''callAssert(''func'', {{'}}''funcName''{{'}}, ...)'''

<code>callAssert</code> calls <code>''func''(...)</code> and checks if the first returned value evaluates to true. If it does, then it returns all the returned values. If not, it throws an error with a message in the form <code>{{'}}''funcName''(''argument_values'') failed'</code>.
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[[Category:Error-handling modules]]
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