Class: Shim

Constructor

new Shim(agent, moduleName, resolvedName, shimName, pkgVersion)

Constructs a shim associated with the given agent instance.

Parameters:

Name	Type	Description
`agent`	Agent	The agent this shim will use.
`moduleName`	string	The name of the module being instrumented.
`resolvedName`	string	The full path to the loaded module.
`shimName`	string	Used to persist shim ids across different instances. This is
`pkgVersion`	string	version of package getting instrumented applicable to instrument that compliments each other across libraries(i.e - koa + koa-route/koa-router)

Source: lib/shim/shim.js, line 35

Members

(readonly) agent :Agent

The agent associated with this shim.

Type:

Agent

Source: lib/shim/shim.js, line 64

(readonly) logger :Logger

The logger for this shim.

Type:

Logger

Source: lib/shim/shim.js, line 86

(readonly) tracer :Tracer

The transaction tracer in use by the agent for the shim.

Type:

Tracer

Source: lib/shim/shim.js, line 75

Methods

applySegment(func, segment, full, context, args, inContextCBopt) → {*}

Sets the given segment as the active one for the duration of the function's execution.

applySegment(func, segment, full, context, args[, inContextCB])

Parameters:

Name	Type	Attributes	Description
`func`	function		The function to execute in the context of the given segment.
`segment`	TraceSegment		The segment to make active for the duration of the function.
`full`	boolean		Indicates if the full lifetime of the segment is bound to this function.
`context`	*		The `this` argument for the function.
`args`	Array.<*>		The arguments to be passed into the function.
`inContextCB`	function	<optional>	The function used to do more instrumentation work. This function is guaranteed to be executed with the segment associated with.

Source: lib/shim/shim.js, line 1162

Returns:

Whatever value func returned.

Type:: *

argsToArray() → {Array}

Like Shim#toArray, but converts arguments to an array.

This is the preferred function, when used with .apply, for converting the arguments object into an actual Array as it will not cause deopts.

Source: lib/shim/shim.js, line 1411
See: Shim#toArray
https://github.com/petkaantonov/bluebird/wiki/Optimization-killers

Returns:

An array containing the elements of arguments.

Type:: Array

assignId(shimName)

Assigns id to shim instance. If shimName is present it will reuse an id otherwise it'll create a unique id.

Parameters:

Name	Type	Description
`shimName`	string	Used to persist shim ids across different instances.

Source: lib/shim/shim.js, line 1699

assignOriginal(wrapped, original, forceOrig)

Assigns the shim id and original on the wrapped item. TODO: Once all wrapping is converted to proxies, we won't need to set this property as the trap on 'get' will return the original for symbols.original. For now, we have to prevent setting this on original.

Parameters:

Name	Type	Description
`wrapped`	*	wrapped item
`original`	*	The item being wrapped.
`forceOrig`	boolean	flag to indicate to overwrite original function

Source: lib/shim/shim.js, line 1682

bindCallbackSegment(spec, args, cbIdx, parentSegmentopt)

Replaces the callback in an arguments array with one that has been bound to the given segment.

bindCallbackSegment(spec, args, cbIdx [, segment])
bindCallbackSegment(spec, obj, property [, segment])

Parameters:

Name	Type	Attributes	Description
`spec`	Spec		spec to original wrapped function, used to call after method with arguments passed to callback
`args`	Array \| object		The arguments array to pull the cb from.
`cbIdx`	number \| string		The index of the callback.
`parentSegment`	TraceSegment	<optional>	The segment to use as the callback segment's parent. Defaults to the currently active segment.

Source: lib/shim/shim.js, line 995
See: Shim#bindSegment

bindPromise(promisenon-null, segmentnon-null) → {Promise}

Binds the given segment to the completion of the Promise. Updates segment timing and resets opaque state.

Parameters:

Name	Type	Description
`promise`	Promise	The Promise to bind.
`segment`	TraceSegment	The segment to bind to the Promise.

Source: lib/shim/shim.js, line 1600

Returns:

The promise to continue with.

Type:: Promise

bindSegment(nodule, propertyopt, segmentopt, nullable, fullopt) → {object|function}

Binds the execution of a function to a single segment.

bindSegment(nodule , property [, segment [, full]])
bindSegment(func [, segment [, full]])

If called with a nodule and a property, the wrapped property will be put back on the nodule. Otherwise, the wrapped function is just returned.

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the property or a single function to bind to a segment.
`property`	string	<optional>	The property to bind. If omitted, the `nodule` parameter is assumed to be the function to bind the segment to.
`segment`	TraceSegment	<optional> <nullable>	The segment to bind the execution of the function to. If omitted or `null` the currently active segment will be bound instead.
`full`	boolean	<optional>	Indicates if the full lifetime of the segment is bound to this function.

Source: lib/shim/shim.js, line 938

Returns:

The first parameter after wrapping.

Type:: object | function

copySegmentParameters(segment, parameters)

Copies the given parameters onto the segment, respecting the current agent configuration.

Parameters:

Name	Type	Description
`segment`	TraceSegment	The segment to copy the parameters onto.
`parameters`	object	The parameters to copy.

Source: lib/shim/shim.js, line 1615

createSegment(name, recorderopt, nullable, parentopt) → (nullable) {TraceSegment}

Creates a new segment.

createSegment(opts)
createSegment(name [, recorder] [, parent])

Parameters:

Name	Type	Attributes	Description
`name`	string		The name to give the new segment.
`recorder`	function	<optional> <nullable>	Optional. A function which will record the segment as a metric. Default is to not record the segment.
`parent`	TraceSegment	<optional>	Optional. The segment to use as the parent. Default is to use the currently active segment.

Source: lib/shim/shim.js, line 1208

Returns:

A new trace segment if a transaction is active, else null is returned.

Type:: TraceSegment

defineProperties(obj, props)

Adds several properties to the given object.

Parameters:

Name	Type	Description
`obj`	object	The object to add the properties to.
`props`	object	A mapping of properties to values to add.

Source: lib/shim/shim.js, line 1490
See: Shim#defineProperty

defineProperty(obj, name, value)

Defines a read-only property on the given object.

Parameters:

Name	Type	Description
`obj`	object	The object to add the property to.
`name`	string	The name of the property to add.
`value`	* \| function	The value to set. If a function is given, it is used as a getter, otherwise the value is directly set as an unwritable property.

Source: lib/shim/shim.js, line 1467

execute(nodule, spec)

Entry point for executing a spec.

Parameters:

Name	Type	Description
`nodule`	object \| function	Class or module containing the function to wrap.
`spec`	Spec	`Spec`

Source: lib/shim/shim.js, line 262

getActiveSegment(objopt) → (nullable) {TraceSegment}

Retrieves the segment associated with the given object, or the currently active segment if no object is given.

getActiveSegment([obj])

An active segment is one whose transaction is still active (e.g. has not ended yet).

Parameters:

Name	Type	Attributes	Description
`obj`	*	<optional>	The object to retrieve a segment from.

Source: lib/shim/shim.js, line 1104

Returns:

The trace segment associated with the given object or the currently active segment if no object is provided or no segment is associated with the object.

Type:: TraceSegment

getName(obj) → {string}

Determine the name of an object.

Parameters:

Name	Type	Description
`obj`	*	The object to get a name for.

Source: lib/shim/shim.js, line 1277

Returns:

The name of the object if it has one, else <anonymous>.

Type:: string

getOriginal(nodule, propertyopt) → {object|function}

Retrieves the original method for a wrapped function.

getOriginal(nodule, property)
getOriginal(func)

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source of the property to get the original of, or a function to unwrap.
`property`	string	<optional>	A property on `nodule` to get the original value of.

Source: lib/shim/shim.js, line 884

Returns:

The original value for the given item.

Type:: object | function

getOriginalOnce(nodule, propertyopt) → {object|function}

Retrieves the value of symbols.original on the wrapped function. Unlike getOriginal this just looks in the direct wrapped function

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source of the property to get the original of, or a function to unwrap.
`property`	string	<optional>	A property on `nodule` to get the original value of.

Source: lib/shim/shim.js, line 907

Returns:

The original value for the given item.

Type:: object | function

getSegment(objopt) → (nullable) {TraceSegment}

Retrieves the segment associated with the given object, or the current segment if no object is given.

getSegment([obj])

Parameters:

Name	Type	Attributes	Description
`obj`	*	<optional>	The object to retrieve a segment from.

Source: lib/shim/shim.js, line 1081

Returns:

The trace segment associated with the given object or the current segment if no object is provided or no segment is associated with the object.

Type:: TraceSegment

interceptPromise(prom, cb) → {Promise}

Executes the given callback when the promise is finalized, whether it is resolved or rejected.

Parameters:

Name	Type	Description
`prom`	Promise	Some kind of promise. Must have a `then` method.
`cb`	function	A function to call when the promise resolves.

Source: lib/shim/shim.js, line 1584

Returns:

A new promise to replace the original one.

Type:: Promise

isArray(obj) → {boolean}

Determines if the given object exists and is an array.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1343

Returns:

True if the object is an array, else false.

Type:: boolean

isAsyncFunction(fn, (function)) → {boolean}

Determines if function is an async function. Note it does not test if the return value of function is a promise or async function

Parameters:

Name	Type	Description
`fn`
`(function)`		function to test if async

Source: lib/shim/shim.js, line 1368

Returns:

True if the function is an async function

Type:: boolean

isBoolean(obj) → {boolean}

Determines if the given object is a boolean literal.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1332

Returns:

True if the object is a boolean literal, else false.

Type:: boolean

isFunction(obj) → {boolean}

Determines if the given object exists and is a function.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1299

Returns:

True if the object is a function, else false.

Type:: boolean

isNull(val) → {boolean}

Determines if the given value is null.

Parameters:

Name	Type	Description
`val`	*	The value to check.

Source: lib/shim/shim.js, line 1379

Returns:

True if the value is null, else false.

Type:: boolean

isNumber(obj) → {boolean}

Determines if the given object is a number literal.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1321

Returns:

True if the object is a number literal, else false.

Type:: boolean

isObject(obj) → {boolean}

Determines if the given object is an Object.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1288

Returns:

True if the object is an Object, else false.

Type:: boolean

isPromise(obj) → {boolean}

Determines if the given object is a promise instance.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1354

Returns:

True if the object is a promise, else false.

Type:: boolean

isString(obj) → {boolean}

Determines if the given object exists and is a string.

Parameters:

Name	Type	Description
`obj`	*	The object to check.

Source: lib/shim/shim.js, line 1310

Returns:

True if the object is a string, else false.

Type:: boolean

isWrapped(nodule, propertyopt) → {boolean}

Determines if the specified function or property exists and is wrapped.

isWrapped(nodule, property)
isWrapped(func)

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the property or a single function to check.
`property`	string	<optional>	The property to check. If omitted, the `nodule` parameter is assumed to be the function to check.

Source: lib/shim/shim.js, line 606
See: Shim#wrap
Shim#bindSegment

Returns:

True if the item exists and has been wrapped.

Type:: boolean

normalizeIndex(arrayLength, idx) → (nullable) {number}

Ensures the given index is a valid index inside the array.

A negative index value is converted to a positive one by adding it to the array length before checking it.

Parameters:

Name	Type	Description
`arrayLength`	number	The length of the array this index is for.
`idx`	number	The index to normalize.

Source: lib/shim/shim.js, line 1431

Returns:

The adjusted index value if it is valid, else null.

Type:: number

once(fn) → {function}

Wraps a function such that it will only be executed once.

Parameters:

Name	Type	Description
`fn`	function	The function to wrap in an execution guard.

Source: lib/shim/shim.js, line 1445

Returns:

A function which will execute fn at most once.

Type:: function

prefixRouteParameters(params) → {object|undefined}

Method for prefixing Route (aka URL) parameters with request.parameters.route

Many web frameworks support adding parameters to routes when defining your API structure, and this function updates those parameters names to be prefixed by request.parameters.route. This is to avoid collision with reserved attribute names, as parameters used to be blindly stored on router span attributes (see https://github.com/newrelic/node-newrelic/issues/1574) in addition to being prefixed by request.parameters.

Route parameters used to be stored under request.parameters.* just like query parameters pre v10, but we now prefix with request.parameter.route to avoid collision in the event an application uses the same name for a query and route parameter. Additionally, we now store the same key on the attributes of the base segment, trace, and router span.

Exported on shim to be used in our Next.js instrumentation, as that instrumentation does not follow the same pattern as all the other web frameworks we support.

Parameters:

Name	Type	Description
`params`	object	Object containing route/url parameter key/value pairs

Source: lib/shim/shim.js, line 2087

Returns:

the updated object, key will now be request.parameters.route.key, value remains untouched

Type:: object | undefined

proxy(source, properties, dest)

Proxies all set/get actions for each given property on dest onto source.

Parameters:

Name	Type	Description
`source`	*	The object on which all the set/get actions will actually occur.
`properties`	string \| Array.<string>	All of the properties to proxy.
`dest`	*	The object which is proxying the source's properties.

Source: lib/shim/shim.js, line 1536

record(nodule, propertiesopt, recordNamer) → {object|function}

Wraps a function with segment creation and binding.

record(nodule, properties, recordNamer)
record(func, recordNamer)

This is shorthand for calling Shim#wrap and manually creating a segment.

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the properties to record, or a single function to record.
`properties`	string \| Array.<string>	<optional>	One or more properties to record. If omitted, the `nodule` parameter is assumed to be the function to record.
`recordNamer`	RecorderFunction		A function which returns a record descriptor that gives the name and type of record we'll make.

Source: lib/shim/shim.js, line 635
See: RecorderFunction
RecorderSpec
Shim#wrap

Returns:

The first parameter, possibly wrapped.

Type:: object | function

setActiveSegment(segment) → {TraceSegment}

Explicitly sets the active segment to the one passed in. This method should only be used if there is no function to tie a segment's timing to.

setActiveSegment(segment)

Parameters:

Name	Type	Description
`segment`	TraceSegment	The segment to set as the active segment.

Source: lib/shim/shim.js, line 1123

Returns:

The segment set as active on the context.

Type:: TraceSegment

setDefaults(objnullable, defaults) → {object}

Performs a shallow copy of each property from defaults only if obj does not already have that property, or the value of the key on obj is null.

Parameters:

Name	Type	Attributes	Description
`obj`	object	<nullable>	The object to copy the defaults onto.
`defaults`	object		A mapping of keys to default values.

Source: lib/shim/shim.js, line 1509

Returns:

The obj with the default values copied onto it. If obj was falsey, then a new object with the defaults copied onto it is returned instead.

Type:: object

shimRequire(filePath) → (nullable) {*}

Loads a node module from the instrumented library's own root directory.

Parameters:

Name	Type	Description
`filePath`	string	A relative path inside the module's directory.

Source: lib/shim/shim.js, line 1561

Returns:

The result of loading the given module. If the module fails to load, null is returned instead.

Type:: *

storeSegment(objnon-null, segmentopt)

Associates a segment with the given object.

storeSegment(obj [, segment])

If no segment is provided, the currently active segment is used.

Parameters:

Name	Type	Attributes	Description
`obj`	*		The object to retrieve a segment from.
`segment`	TraceSegment	<optional>	The segment to link the object to.

Source: lib/shim/shim.js, line 1139

toArray(obj) → {Array.<*>}

Converts an array-like object into an array.

Parameters:

Name	Type	Description
`obj`	*	The array-like object (i.e. `arguments`).

Source: lib/shim/shim.js, line 1391

Returns:

An instance of Array containing the elements of the array-like.

Type:: Array.<*>

unwrap(nodule, propertiesopt) → {object|function}

Unwraps one item, revealing the underlying value. If item is wrapped multiple times, the unwrap will not occur as we cannot safely unwrap.

unwrap(nodule, property)
unwrap(func)

If called with a nodule and properties, the unwrapped value will be put back on the nodule. Otherwise, the unwrapped function is just returned.

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the properties to unwrap, or a single function to unwrap.
`properties`	string \| Array.<string>	<optional>	One or more properties to unwrap. If omitted, the `nodule` parameter is assumed to be the function to unwrap.

Source: lib/shim/shim.js, line 842

Returns:

The first parameter after unwrapping.

Type:: object | function

wrap(nodule, propertiesopt, spec, argsopt) → {object|function}

Executes the provided spec on one or more objects.

wrap(nodule, properties, spec [, args])
wrap(func, spec [, args])

When called with a nodule and one or more properties, the spec will be executed on each property listed and the return value put back on the nodule.

When called with just a function, the spec will be executed on the function and the return value of the spec simply passed back.

The wrapped version will have the same prototype as the original method.

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the properties to wrap, or a single function to wrap.
`properties`	string \| Array.<string>	<optional>	One or more properties to wrap. If omitted, the `nodule` parameter is assumed to be the function to wrap.
`spec`	Spec \| WrapFunction		The spec for wrapping these items.
`args`	Array.<*>	<optional>	Optional extra arguments to be sent to the spec when executing it.

Source: lib/shim/shim.js, line 300
See: WrapFunction

Returns:

The first parameter to this function, after wrapping it or its properties.

Type:: object | function

wrapClass(nodule, propertiesopt, spec, argsopt) → {object|function}

Wraps a class constructor using a subclass with pre- and post-construction hooks.

wrapClass(nodule, properties, spec [, args])
wrapClass(func, spec [, args])

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the properties to wrap, or a single function to wrap.
`properties`	string \| Array.<string>	<optional>	One or more properties to wrap. If omitted, the `nodule` parameter is assumed to be the constructor to wrap.
`spec`	ClassWrapSpec \| ConstructorHookFunction		The spec for wrapping the returned value from the properties or a post hook.
`args`	Array.<*>	<optional>	Optional extra arguments to be sent to the spec when executing it.

Source: lib/shim/shim.js, line 524
See: Shim#wrap

Returns:

The first parameter to this function, after wrapping it or its properties.

Type:: object | function

wrapExport(nodule, spec) → {*}

Wraps the actual module being instrumented to change what require returns.

wrapExport(nodule, spec)

Parameters:

Name	Type	Description
`nodule`	*	The original export to replace with our new one.
`spec`	WrapFunction	A wrapper function. The return value from this spec is what will replace the export.

Source: lib/shim/shim.js, line 565

Returns:

The return value from spec.

Type:: *

wrapReturn(nodule, propertiesopt, spec, argsopt) → {object|function}

Executes the provided spec with the return value of the given properties.

wrapReturn(nodule, properties, spec [, args])
wrapReturn(func, spec [, args])

If the wrapper is executed with new then the wrapped function will also be called with new. This feature should only be used with factory methods disguised as classes. Normally Shim#wrapClass should be used to wrap constructors instead.

Parameters:

Name	Type	Attributes	Description
`nodule`	object \| function		The source for the properties to wrap, or a single function to wrap.
`properties`	string \| Array.<string>	<optional>	One or more properties to wrap. If omitted, the `nodule` parameter is assumed to be the function to wrap.
`spec`	Spec \| function		The spec for wrapping the returned value from the properties.
`args`	Array.<*>	<optional>	Optional extra arguments to be sent to the spec when executing it.

Source: lib/shim/shim.js, line 382
See: Shim#wrap

Returns:

The first parameter to this function, after wrapping it or its properties.

Type:: object | function