The function that is being deprecated.
A warning message to display when the deprecated function is invoked.
Optional code: stringA deprecation code. See the list of deprecated APIs for a list of codes.
The util.deprecate() method wraps fn (which may be a function or class) in
such a way that it is marked as deprecated.
const util = require('util');
exports.obsoleteFunction = util.deprecate(() => {
// Do something here.
}, 'obsoleteFunction() is deprecated. Use newShinyFunction() instead.');
When called, util.deprecate() will return a function that will emit aDeprecationWarning using the 'warning' event. The warning will
be emitted and printed to stderr the first time the returned function is
called. After the warning is emitted, the wrapped function is called without
emitting a warning.
If the same optional code is supplied in multiple calls to util.deprecate(),
the warning will be emitted only once for that code.
const util = require('util');
const fn1 = util.deprecate(someFunction, someMessage, 'DEP0001');
const fn2 = util.deprecate(someOtherFunction, someOtherMessage, 'DEP0001');
fn1(); // Emits a deprecation warning with code DEP0001
fn2(); // Does not emit a deprecation warning because it has the same code
If either the --no-deprecation or --no-warnings command-line flags are
used, or if the process.noDeprecation property is set to trueprior to
the first deprecation warning, the util.deprecate() method does nothing.
If the --trace-deprecation or --trace-warnings command-line flags are set,
or the process.traceDeprecation property is set to true, a warning and a
stack trace are printed to stderr the first time the deprecated function is
called.
If the --throw-deprecation command-line flag is set, or theprocess.throwDeprecation property is set to true, then an exception will be
thrown when the deprecated function is called.
The --throw-deprecation command-line flag and process.throwDeprecationproperty take precedence over --trace-deprecation andprocess.traceDeprecation.
The deprecated function wrapped to emit a warning.
The function that is being deprecated.
A warning message to display when the deprecated function is invoked.
Optional code: stringA deprecation code. See the list of deprecated APIs for a list of codes.
Generated using TypeDoc
The
util.deprecate()method wrapsfn(which may be a function or class) in such a way that it is marked as deprecated.When called,
util.deprecate()will return a function that will emit aDeprecationWarningusing the'warning'event. The warning will be emitted and printed tostderrthe first time the returned function is called. After the warning is emitted, the wrapped function is called without emitting a warning.If the same optional
codeis supplied in multiple calls toutil.deprecate(), the warning will be emitted only once for thatcode.If either the
--no-deprecationor--no-warningscommand-line flags are used, or if theprocess.noDeprecationproperty is set totrueprior to the first deprecation warning, theutil.deprecate()method does nothing.If the
--trace-deprecationor--trace-warningscommand-line flags are set, or theprocess.traceDeprecationproperty is set totrue, a warning and a stack trace are printed tostderrthe first time the deprecated function is called.If the
--throw-deprecationcommand-line flag is set, or theprocess.throwDeprecationproperty is set totrue, then an exception will be thrown when the deprecated function is called.The
--throw-deprecationcommand-line flag andprocess.throwDeprecationproperty take precedence over--trace-deprecationandprocess.traceDeprecation.Returns
The deprecated function wrapped to emit a warning.