1 files changed, 88 insertions, 0 deletions
diff --git a/node_modules/append-transform/index.js b/node_modules/append-transform/index.js
new file mode 100644
index 000000000..084195403
--- /dev/null
+++ b/node_modules/append-transform/index.js
@@ -0,0 +1,88 @@
+'use strict';
+
+var js = require('default-require-extensions/js');
+
+module.exports = appendTransform;
+
+var count = 0;
+
+function appendTransform(transform, ext, extensions) {
+	// Generate a unique key for this transform
+	var key = __dirname + count; // eslint-disable-line
+	count++;
+	ext = ext || '.js';
+	extensions = extensions || require.extensions;
+
+	var forwardGet;
+	var forwardSet;
+
+	var descriptor = Object.getOwnPropertyDescriptor(extensions, ext) || {value: js, configurable: true};
+
+	if (
+		((descriptor.get || descriptor.set) && !(descriptor.get && descriptor.set)) ||
+		!descriptor.configurable
+	) {
+		throw new Error('Somebody did bad things to require.extensions["' + ext + '"]');
+	}
+
+	if (descriptor.get) {
+		// wrap a previous append-transform install and pass through to the getter/setter pair it created
+		forwardGet = function () {
+			return descriptor.get();
+		};
+		forwardSet = function (val) {
+			descriptor.set(val);
+			return forwardGet();
+		};
+	} else {
+		forwardGet = function () {
+			return descriptor.value;
+		};
+		forwardSet = function (val) {
+			descriptor.value = val;
+			return val;
+		};
+	}
+
+	function wrapCustomHook(hook) {
+		return function (module, filename) {
+			// We wrap every added extension, but we only apply the transform to the one on top of the stack
+			if (!module[key]) {
+				module[key] = true;
+
+				var originalCompile = module._compile;
+
+				module._compile = function replacementCompile(code, filename) {
+					module._compile = originalCompile;
+					code = transform(code, filename);
+					module._compile(code, filename);
+				};
+			}
+
+			hook(module, filename);
+		};
+	}
+
+	// wrap the original
+	forwardSet(wrapCustomHook(forwardGet()));
+
+	var hooks = [forwardGet()];
+
+	function setCurrentHook(hook) {
+		var restoreIndex = hooks.indexOf(hook);
+		if (restoreIndex === -1) {
+			hooks.push(forwardSet(wrapCustomHook(hook)));
+		} else {
+			// we have already scene this hook, and it is being reverted (proxyquire, etc) - don't wrap again.
+			hooks.splice(restoreIndex + 1, hooks.length);
+			forwardSet(hook);
+		}
+	}
+
+	Object.defineProperty(extensions, ext, {
+		configurable: true,
+		enumerable: true,
+		get: forwardGet,
+		set: setCurrentHook
+	});
+}