Configures v8 flags at runtime.
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example use-strict example and improving readme example Jun 30, 2014
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src implemening and testing FlagList functions Jun 30, 2014
test implemening and testing FlagList functions Jun 30, 2014
v8 properly generating cc stubs to get flags Jun 28, 2014
.gitignore generating flag_definitions.h from node version Jun 30, 2014
.jsdocrc fixing docs Jun 26, 2014
.travis.yml
LICENSE "initial repository" Jun 25, 2014
README.md
binding.gyp implemening and testing FlagList functions Jun 30, 2014
flags-0.10.md all separate harmony flags Jun 30, 2014
flags-0.11.md all separate harmony flags Jun 30, 2014
flags-0.8.md all separate harmony flags Jun 30, 2014
index.js
package.json 0.1.2 Jul 1, 2014
test.sh

README.md

v8-flags build status

Configures v8 flags at runtime.

// use-strict-violator.js
a = "I'm the trouble starter, punking instigator"

module.exports = a;
var flags = require('v8-flags').flags;
console.log('inital use strict', flags.use_strict());

flags.use_strict(true);
console.log('set use strict to', flags.use_strict());

try {
  require('./use-strict-violator');
} catch(err) {
  console.error('FAIL:', err);
}

flags.use_strict(false);
console.log('set use strict to', flags.use_strict());

var violator = require('./use-strict-violator');
console.log(violator)
inital use strict false
set use strict to true
FAIL: [ReferenceError: a is not defined]
set use strict to false
I'm the trouble starter, punking instigator

Installation

npm install v8-flags

Contributions

I am doing my best to document each flag, but am hoping for others especially the ones with insider knowledge to supply useful comments.

I made this as easy as possible, all you have to do is add/edit the .md file with the name of the flag in this folder and run npm run flag-doc to update all documentation with the added details.

API

The different versions of v8 and thus Node.js have different flags and therefore the API fluctuates somewhat between the versions. The API is generated on install to match the Node.js version you are using.

The flags for the currently latest Node.js versions 0.8, 0.10 and 0.11 are documented in the following locations:

The below API allows to access and configure these flags.

Table of Contents generated with DocToc

  • enforceFlagImplications()
  • flags()
  • listFlags() → {Object}
  • meta() → {Array.}
  • printHelp()
  • resetAllFlags()
  • enforceFlagImplications()

    Enforces all flag implications.

    Source:

    flags()

    Exposes methods to get and set v8 flags.

    Example

    var flags = require('v8-flags').flags;
    console.log(flags.use_strict()); // false
    flags.use_strict(true)
    console.log(flags.use_strict()); // true
    Source:

    listFlags() → {Object}

    Lists all flags along with their current value.

    Source:
    Returns:

    key/value pair for each flag

    Type
    Object

    meta() → {Array.<Object>}

    The meta data for the flags.

    It is initialized on startup from the definitions found in C++ land.

    Source:
    Returns:

    array of objects with the folloing properties each

    • name: flag name
    • default: default setting of the flag
    • type: type of the flag
    • description: the description of the flag
    • readonly: set true if flag cannot be set
    • configurable: set true if setting the flag at runtime has the desired effect
    • implications: flags that will be set to true whenever this flag is true and enforceFlagImplications is called
    • negativeImplications: flags that will be set to false whenever this flag is false and enforceFlagImplications is called
    Type
    Array.<Object>

    printHelp()

    Prints flag help to the console.

    Source:

    resetAllFlags()

    Resets all flags to their default values

    Source:

    generated with docme

    License

    MIT