Notes

/**
* Module dependencies.
*/

var fs = require('fs'),
path = require('path'),
fileURLToPath = require('file-uri-to-path'),
join = path.join,
dirname = path.dirname,
exists =
(fs.accessSync &&
function(path) {
try {
fs.accessSync(path);
} catch (e) {
return false;
}
return true;
}) ||
fs.existsSync ||
path.existsSync,
defaults = {
arrow: process.env.NODE_BINDINGS_ARROW || ' → ',
compiled: process.env.NODE_BINDINGS_COMPILED_DIR || 'compiled',
platform: process.platform,
arch: process.arch,
nodePreGyp:
'node-v' +
process.versions.modules +
'-' +
process.platform +
'-' +
process.arch,
version: process.versions.node,
bindings: 'bindings.node',
try: [
// node-gyp's linked version in the "build" dir
['module_root', 'build', 'bindings'],
// node-waf and gyp_addon (a.k.a node-gyp)
['module_root', 'build', 'Debug', 'bindings'],
['module_root', 'build', 'Release', 'bindings'],
// Debug files, for development (legacy behavior, remove for node v0.9)
['module_root', 'out', 'Debug', 'bindings'],
['module_root', 'Debug', 'bindings'],
// Release files, but manually compiled (legacy behavior, remove for node v0.9)
['module_root', 'out', 'Release', 'bindings'],
['module_root', 'Release', 'bindings'],
// Legacy from node-waf, node <= 0.4.x
['module_root', 'build', 'default', 'bindings'],
// Production "Release" buildtype binary (meh...)
['module_root', 'compiled', 'version', 'platform', 'arch', 'bindings'],
// node-qbs builds
['module_root', 'addon-build', 'release', 'install-root', 'bindings'],
['module_root', 'addon-build', 'debug', 'install-root', 'bindings'],
['module_root', 'addon-build', 'default', 'install-root', 'bindings'],
// node-pre-gyp path ./lib/binding/{node_abi}-{platform}-{arch}
['module_root', 'lib', 'binding', 'nodePreGyp', 'bindings']
]
};

/**
* The main `bindings()` function loads the compiled bindings for a given module.
* It uses V8's Error API to determine the parent filename that this function is
* being invoked from, which is then used to find the root directory.
*/

function bindings(opts) {
// Argument surgery
if (typeof opts == 'string') {
opts = { bindings: opts };
} else if (!opts) {
opts = {};
}

// maps `defaults` onto `opts` object
Object.keys(defaults).map(function(i) {
if (!(i in opts)) opts[i] = defaults[i];
});

// Get the module root
if (!opts.module_root) {
opts.module_root = exports.getRoot(exports.getFileName());
}

// Ensure the given bindings name ends with .node
if (path.extname(opts.bindings) != '.node') {
opts.bindings += '.node';
}

// https://github.com/webpack/webpack/issues/4175#issuecomment-342931035
var requireFunc =
typeof __webpack_require__ === 'function'
? __non_webpack_require__
: require;

var tries = [],
i = 0,
l = opts.try.length,
n,
b,
err;

for (; i < l; i++) {
n = join.apply(
null,
opts.try[i].map(function(p) {
return opts[p] || p;
})
);
tries.push(n);
try {
b = opts.path ? requireFunc.resolve(n) : requireFunc(n);
if (!opts.path) {
b.path = n;
}
return b;
} catch (e) {
if (e.code !== 'MODULE_NOT_FOUND' &&
e.code !== 'QUALIFIED_PATH_RESOLUTION_FAILED' &&
!/not find/i.test(e.message)) {
throw e;
}
}
}

err = new Error(
'Could not locate the bindings file. Tried:n' +
tries
.map(function(a) {
return opts.arrow + a;
})
.join('n')
);
err.tries = tries;
throw err;
}
module.exports = exports = bindings;

/**
* Gets the filename of the JavaScript file that invokes this function.
* Used to help find the root directory of a module.
* Optionally accepts an filename argument to skip when searching for the invoking filename
*/

exports.getFileName = function getFileName(calling_file) {
var origPST = Error.prepareStackTrace,
origSTL = Error.stackTraceLimit,
dummy = {},
fileName;

Error.stackTraceLimit = 10;

Error.prepareStackTrace = function(e, st) {
for (var i = 0, l = st.length; i < l; i++) {
fileName = st[i].getFileName();
if (fileName !== __filename) {
if (calling_file) {
if (fileName !== calling_file) {
return;
}
} else {
return;
}
}
}
};

// run the 'prepareStackTrace' function above
Error.captureStackTrace(dummy);
dummy.stack;

// cleanup
Error.prepareStackTrace = origPST;
Error.stackTraceLimit = origSTL;

// handle filename that starts with "file://"
var fileSchema = 'file://';
if (fileName.indexOf(fileSchema) === 0) {
fileName = fileURLToPath(fileName);
}

return fileName;
};

/**
* Gets the root directory of a module, given an arbitrary filename
* somewhere in the module tree. The "root directory" is the directory
* containing the `package.json` file.
*
* In: /home/nate/node-native-module/lib/index.js
* Out: /home/nate/node-native-module
*/

exports.getRoot = function getRoot(file) {
var dir = dirname(file),
prev;
while (true) {
if (dir === '.') {
// Avoids an infinite loop in rare cases, like the REPL
dir = process.cwd();
}
if (
exists(join(dir, 'package.json')) ||
exists(join(dir, 'node_modules'))
) {
// Found the 'package.json' file or 'node_modules' dir; we're done
return dir;
}
if (prev === dir) {
// Got to the top
throw new Error(
'Could not find module root given file: "' +
file +
'". Do you have a `package.json` file? '
);
}
// Try the parent dir next
prev = dir;
dir = join(dir, '..');
}
};