devtools-protocol

Debugger

Debugger domain exposes JavaScript debugging capabilities. It allows setting and removing breakpoints, stepping through execution, exploring stack traces, etc.

Methods	enable, disable, getPossibleBreakpoints, setBreakpointsActive, setBreakpointByUrl, setBreakpoint, removeBreakpoint, stepOver, stepInto, stepOut, pause, resume, getScriptSource, setPauseOnExceptions, evaluateOnCallFrame, setVariableValue, setBlackboxPatterns
Events	scriptParsed, breakpointResolved, paused, resumed
Types	BreakpointId, CallFrameId, Location, BreakLocation, CallFrame, Scope

Methods

enable

Enables debugger for the given page. Clients should not assume that the debugging has been enabled until the result for this command is received.

disable

Disables debugger for given page.

getPossibleBreakpoints

Returns possible locations for breakpoint. scriptId in start and end range locations should be the same.

Parameters
start	`Location`	Start of range to search possible breakpoint locations in.
end	`Location`	End of range to search possible breakpoint locations in (excluding). When not specified, end of scripts is used as end of range.

Returns
locations	`BreakLocation`	List of the possible breakpoint locations.

setBreakpointsActive

Activates / deactivates all breakpoints on the page.

Parameters
active	`boolean`	New value for breakpoints active state.

setBreakpointByUrl

Sets JavaScript breakpoint at given location specified either by URL or URL regex. Once this command is issued, all existing parsed scripts will have breakpoints resolved and returned in locations property. Further matching script parsing will result in subsequent breakpointResolved events issued. This logical breakpoint will survive page reloads.

Parameters
lineNumber	`integer`	Line number to set breakpoint at.
url optional	`string`	URL of the resources to set breakpoint on.
urlRegex optional	`string`	Regex pattern for the URLs of the resources to set breakpoints on. Either `url` or `urlRegex` must be specified.
columnNumber optional	`integer`	Offset in the line to set breakpoint at.
condition optional	`string`	Expression to use as a breakpoint condition. When specified, debugger will only stop on the breakpoint if this expression evaluates to true.

Returns
breakpointId	`BreakpointId`	Id of the created breakpoint for further reference.
locations	`Location[]`	List of the locations this breakpoint resolved into upon addition.

setBreakpoint

Sets JavaScript breakpoint at a given location.

Parameters
location	`Location`	Location to set breakpoint in.
condition optional	`string`	Expression to use as a breakpoint condition. When specified, debugger will only stop on the breakpoint if this expression evaluates to true.

Returns
breakpointId	`BreakpointId`	Id of the created breakpoint for further reference.
actualLocation	`Location`	Location this breakpoint resolved into.

removeBreakpoint

Removes JavaScript breakpoint.

Parameters
breakpointId	`BreakpointId`

stepOver

Steps over the statement.

stepInto

Steps into the function call.

stepOut

Steps out of the function call.

pause

Stops on the next JavaScript statement.

resume

Resumes JavaScript execution.

getScriptSource

Returns source for the script with given id.

Parameters
scriptId	`Runtime.ScriptId`	Id of the script to get source for.

Returns
scriptSource	`string`	Script source.

setPauseOnExceptions

Defines pause on exceptions state. Can be set to stop on all exceptions, uncaught exceptions or no exceptions. Initial pause on exceptions state is none.

Parameters
state	`string` Allowed values: none, uncaught, all	Pause on exceptions mode.

evaluateOnCallFrame

Evaluates expression on a given call frame.

Parameters
callFrameId	`CallFrameId`	Call frame identifier to evaluate on.
expression	`string`	Expression to evaluate.

Returns
result	`Runtime.RemoteObject`	Object wrapper for the evaluation result.

setVariableValue

Changes value of variable in a callframe. Object-based scopes are not supported and must be mutated manually.

Parameters
scopeNumber	`integer`	0-based number of scope as was listed in scope chain. Only 'local', 'closure' and 'catch' scope types are allowed. Other scopes could be manipulated manually.
variableName	`string`	Variable name.
newValue	`Runtime.CallArgument`	New variable value.
callFrameId	`CallFrameId`	Id of callframe that holds variable.

setBlackboxPatterns

Replace previous blackbox patterns with passed ones. Forces backend to skip stepping/pausing in scripts with url matching one of the patterns. The debugger will try to leave blackboxed script by performing ‘step in’ several times, finally resorting to ‘step out’ if unsuccessful.

Parameters
patterns	`string[]`	Array of regexps that will be used to check script url for blackbox state.

Events

scriptParsed

Fired when the script is parsed. This event is also fired for all known and uncollected scripts upon enabling debugger.

Parameters
scriptId	`Runtime.ScriptId`	Identifier of the script parsed.
url	`string`	URL or name of the script parsed (if any).
startLine	`integer`	Line offset of the script within the resource with given URL (for script tags).
startColumn	`integer`	Column offset of the script within the resource with given URL.
endLine	`integer`	Last line of the script.
endColumn	`integer`	Length of the last line of the script.
executionContextId	`Runtime.ExecutionContextId`	Specifies script creation context.
sourceMapURL optional	`string`	URL of source map associated with script (if any).
length optional	`integer`	This script length.
msMimeType optional	`string`	This is the mime type.

breakpointResolved

Fired when breakpoint is resolved to an actual script and location.

Parameters
breakpointId	`BreakpointId`	Breakpoint unique identifier.
location	`Location`	Actual breakpoint location.

paused

Fired when the debuggers breaks for a breakpoint or exception.

Parameters
callFrames	`CallFrame[]`	Call stack the debugger stopped on.
reason	`string` Allowed values: breakpoint, step, exception, other, EventListener	Pause reason.
data optional	`object`	Object containing break-specific auxiliary properties.
hitBreakpoints optional	`string[]`	Hit breakpoints IDs
asyncStackTrace optional	`StackTrace`	JavaScript async stack trace.

resumed

Fired when the debugger resumes execution.

Types

BreakpointId `string`

Breakpoint identifier.

CallFrameId `string`

Call frame identifier.

Location `object`

Location in the source code.

Properties
scriptId	`Runtime.ScriptId`	Script identifier as reported in the `Debugger.scriptParsed`.
lineNumber	`integer`	Line number in the script (0-based).
columnNumber optional	`integer`	Column number in the script (0-based).
msLength	`integer`	Microsoft: Length of code (i.e. number of characters) at this call frame.

BreakLocation `object`

Break location in the source code.

Properties
scriptId	`Runtime.ScriptId`	Script identifier as reported in the `Debugger.scriptParsed`.
lineNumber	`integer`	Line number in the script (0-based).
columnNumber optional	`integer`	Column number in the script (0-based).
msLength	`integer`	Microsoft: Length of code (i.e. number of characters) at this call frame.
type optional	`string`	Allowed values: debuggerStatement, call, return.

CallFrame `object`

JavaScript call frame. Array of call frames form the call stack.

Properties
callFrameId	`CallFrameId`	Call frame identifier. This identifier is only valid while the debugger is paused.
functionName	`string`	Name of the JavaScript function called on this call frame.
functionLocation optional	`Location`	Location in the source code.
location	`Location`	Location in the source code.
url	`string`	JavaScript script name or url.
scopeChain	`Scope[]`	Scope chain for this call frame.
this	`Runtime.RemoteObject`	`this` object for this call frame.
returnValue optional	`Runtime.RemoteObject`	The value being returned, if the function is at return point.

Scope `object`

Scope description.

Properties
type	`string` Allowed values: global, local, with, closure, catch, block, script, eval, module, return	Scope type.
object	`Runtime.RemoteObject`	Object representing the scope. For `global` and `with` scopes it represents the actual object; for the rest of the scopes, it is artificial transient object enumerating scope variables as its properties.
name optional	`string`
startLocation optional	`Location`	Location in the source code where scope starts
endLocation optional	`Location`	Location in the source code where scope ends

Dependencies

Runtime

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