callsite-record


Create fancy log entries for errors and function call sites.

For Error:
``js
'use strict';

const createCallsiteRecord = require('callsite-record');

function myFunc() {
throw new Error('Yo!');
}

try {
myFunc();
}
catch(err) {
console.log(createCallsiteRecord({ forError: err }).renderSync());
}

`

⬇

!example

For function call up in the stack:

`js
'use strict';

const createCallsiteRecord = require('callsite-record');

function func2 () {
(function func1 () {
console.log(createCallsiteRecord({ byFunctionName: 'func2' }).renderSync());
})();
}

func2();
`

⬇

!example

Additional goodies:
- Use renderers for different output formats, e.g. to produce output in HTML.
- Use stack filter to produce clean and beautiful stacks, e.g. removing Node lib internal calls.

Install


`
npm install callsite-record
`

API

$3

You can generate a callsite for any stack frame, not only the topmost one. Use the isCallsiteFrame function to select
a frame. This function is called for each frame starting from the top. Return true for the desired frame to generate
the callsite.

Example:
`js
const createCallsiteRecord = require('callsite-record');

try {
throw new Error("We're doomed");
}
catch(err) {
const record = createCallsiteRecord({ forError: err });
}
`

$3

Creates CallsiteRecord for the function up in the call stack specified by byFunctionName. You can optionally specify a
typeName if the function is a method. If the function is a constructor set byFunctionName to constructor.

Example:
`js
const createCallsiteRecord = require('callsite-record');

(function func1() {
(function func2() {
(function func3() {
const record = createCallsiteRecord({ byFunctionName: 'func2' });
})();
})();
})();
`

You can specify processFrameFn function, which will process every frame in callstack. It's usefull when you need to
enable frame processing like source-maps-support.

Example:
`js
const createCallsiteRecord = require('callsite-record');
const wrapCallSite = require('source-map-support').wrapCallSite;

try {
throw new Error("We're doomed");
}
catch(err) {
const record = createCallsiteRecord({ forError: err, processFrameFn: wrapCallSite });
}

(function func1() {
(function func2() {
(function func3() {
const record = createCallsiteRecord({ byFunctionName: 'func2', processFrameFn: wrapCallSite });
})();
})();
})();
`

$3

#### CallsiteRecord.render([renderOptions]) → Promise<String>
Renders call site record to the string.

Example:
`js
record.render().then(str => console.log(str));
`

#### CallsiteRecord.renderSync([renderOptions]) → String
Sync version of the CallsiteRecord.render.

##### renderOptions.frameSize
Specifies the number of lines rendered above and below the call site in the code frame. Default: 5.

Example:
`js
console.log(record.renderSync({ frameSize: 0 }));
// > 12 | func1();
// ...

console.log(record.renderSync({ frameSize: 1 }));
// 11 |(function func2() {
// > 12 | func1();
// 13 |})();
// ...
`

##### renderOptions.codeFrame
Specifies if code frame should be rendered. If disabled only stack will be rendered. Default: true.

##### renderOptions.stack
Specifies if stack trace should be rendered in addition to the code frame. Default: true.

##### renderOptions.stackFilter
Function that will be used to filter stack frames. Function accepts 2 arguments:
- stackFrame - stack entry.
- idx - index of the frame.
- isV8StackFrame - if true then stackFrame is a V8 CallSite object.
Otherwise it's a StackFrame object.

Default: null.

Example:
`js
const sep = require('path').sep;

// Remove node core lib calls from the stack trace
record.renderSync({ stackFilter: frame => frame.getFileName().indexOf(sep) > -1 });
`

##### renderOptions.renderer
Specifies the output format of the rendering. Default: renderers.default. You can pass your own
renderer object (example implementations) or use
one of the built-in renderers:

###### renderers.default
Provides ANSI-colored output as shown above.

Usage:
`js
const defaultRenderer = require('callsite-record').renderers.default;

record.renderSync({ renderer: defaultRenderer });
`

###### renderers.noColor
Same as default renderer but without colors.

Usage:
`js
const noColorRenderer = require('callsite-record').renderers.noColor;

record.renderSync({ renderer: noColorRenderer });
`

###### renderers.html
Outputs HTML that can be later decorated with the CSS and embeded into the web page. Example output.

Usage:
`js
const htmlRenderer = require('callsite-record').renderers.html;

record.renderSync({ renderer: html });
``

Related

* is-es2016-keyword - Determine if string is an ES2016 keyword.
* highlight-es - Highlight ECMAScript syntax for the console or any other medium.

Author

Ivan Nikulin (ifaaan@gmail.com)