Moving binding loading a function

This removes the need to mess with `require.cache` in tests to test
the unsupported platform error message. I've run into issues a couple
times related to messing with the require cache.

lib/binding.js

+/*!
+ * node-sass: lib/binding.js
+ */
+
+var errors = require('./errors');
+
+/**
+ * Require binding
+ */
+module.exports = function(ext) {
+  if (!ext.hasBinary(ext.getBinaryPath())) {
+    if (!ext.isSupportedEnvironment()) {
+      throw new Error(errors.unsupportedEnvironment());
+    } else {
+      throw new Error(errors.missingBinary());
+    }
+  }
+
+  return require(ext.getBinaryPath());
+};

lib/index.js

@@ -4,23 +4,14 @@
 
 var path = require('path'),
   clonedeep = require('lodash.clonedeep'),
-  errors = require('./errors'),
   assign = require('lodash.assign'),
   sass = require('./extensions');
 
-if (!sass.hasBinary(sass.getBinaryPath())) {
-  if (!sass.isSupportedEnvironment()) {
-    throw new Error(errors.unsupportedEnvironment());
-  } else {
-    throw new Error(errors.missingBinary());
-  }
-}
-
 /**
  * Require binding
  */
 
-var binding = require(sass.getBinaryPath());
+var binding = require('./binding')(sass);
 
 /**
  * Get input file

test/api.js

@@ -1839,133 +1839,4 @@ describe('api', function() {
       done();
     });
   });
-
-  describe('binding', function() {
-    beforeEach(function() {
-      delete require.cache[sassPath];
-    });
-
-    afterEach(function() {
-      delete require.cache[sassPath];
-    });
-
-    describe('missing error', function() {
-      it('should be useful', function() {
-        process.env.SASS_BINARY_NAME = 'Linux-x64-48';
-        assert.throws(
-          function() { require(sassPath); },
-          new RegExp('Missing binding.*?\\' + path.sep + 'vendor\\' + path.sep)
-        );
-      });
-
-      it('should list currently installed bindings', function() {
-        assert.throws(
-          function() { require(sassPath); },
-          function(err) {
-            var etx = require('../lib/extensions');
-
-            delete process.env.SASS_BINARY_NAME;
-
-            if ((err instanceof Error)) {
-              return err.message.indexOf(
-                etx.getHumanEnvironment(etx.getBinaryName())
-              ) !== -1;
-            }
-          }
-        );
-      });
-    });
-
-    describe('on unsupported environment', function() {
-      describe('with an unsupported architecture', function() {
-        var prevValue;
-
-        beforeEach(function() {
-          prevValue = process.arch;
-
-          Object.defineProperty(process, 'arch', {
-            get: function () { return 'foo'; }
-          });
-        });
-
-        afterEach(function() {
-          process.arch = prevValue;
-        });
-
-        it('should error', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Node Sass does not yet support your current environment'
-          );
-        });
-
-        it('should inform the user the architecture is unsupported', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Unsupported architecture (foo)'
-          );
-        });
-      });
-
-      describe('with an unsupported platform', function() {
-        var prevValue;
-
-        beforeEach(function() {
-          prevValue = process.platform;
-
-          Object.defineProperty(process, 'platform', {
-            get: function () { return 'bar'; }
-          });
-        });
-
-        afterEach(function() {
-          process.platform = prevValue;
-        });
-
-        it('should error', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Node Sass does not yet support your current environment'
-          );
-        });
-
-        it('should inform the user the platform is unsupported', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Unsupported platform (bar)'
-          );
-        });
-      });
-
-      describe('with an unsupported runtime', function() {
-        var prevValue;
-
-        beforeEach(function() {
-          prevValue = process.versions.modules;
-
-          Object.defineProperty(process.versions, 'modules', {
-            get: function () { return 'baz'; }
-          });
-        });
-
-        afterEach(function() {
-          process.versions.modules = prevValue;
-        });
-
-        it('should error', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Node Sass does not yet support your current environment'
-          );
-        });
-
-        it('should inform the user the runtime is unsupported', function() {
-          assert.throws(
-            function() { require(sassPath); },
-            'Unsupported runtime (baz)'
-          );
-        });
-      });
-    });
-  });
 });

test/binding.js

+/*eslint new-cap: ["error", {"capIsNewExceptions": ["Color"]}]*/
+
+var assert = require('assert'),
+  path = require('path'),
+  etx = require('../lib/extensions'),
+  binding = process.env.NODESASS_COV
+      ? require('../lib-cov/binding')
+      : require('../lib/binding');
+
+describe('binding', function() {
+  describe('missing error', function() {
+    it('should be useful', function() {
+      process.env.SASS_BINARY_NAME = 'Linux-x64-48';
+      assert.throws(
+        function() { binding(etx); },
+        function(err) {
+          var re = new RegExp('Missing binding.*?\\' + path.sep + 'vendor\\' + path.sep);
+          if ((err instanceof Error)) {
+            return re.test(err);
+          }
+        }
+      );
+    });
+
+    it('should list currently installed bindings', function() {
+      assert.throws(
+        function() { binding(etx); },
+        function(err) {
+          var etx = require('../lib/extensions');
+
+          delete process.env.SASS_BINARY_NAME;
+
+          if ((err instanceof Error)) {
+            return err.message.indexOf(
+              etx.getHumanEnvironment(etx.getBinaryName())
+            ) !== -1;
+          }
+        }
+      );
+    });
+  });
+
+  describe('on unsupported environment', function() {
+    describe('with an unsupported architecture', function() {
+      var prevValue;
+
+      beforeEach(function() {
+        prevValue = process.arch;
+
+        Object.defineProperty(process, 'arch', {
+          get: function () { return 'foo'; }
+        });
+      });
+
+      afterEach(function() {
+        process.arch = prevValue;
+      });
+
+      it('should error', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Node Sass does not yet support your current environment'
+        );
+      });
+
+      it('should inform the user the architecture is unsupported', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Unsupported architecture (foo)'
+        );
+      });
+    });
+
+    describe('with an unsupported platform', function() {
+      var prevValue;
+
+      beforeEach(function() {
+        prevValue = process.platform;
+
+        Object.defineProperty(process, 'platform', {
+          get: function () { return 'bar'; }
+        });
+      });
+
+      afterEach(function() {
+        process.platform = prevValue;
+      });
+
+      it('should error', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Node Sass does not yet support your current environment'
+        );
+      });
+
+      it('should inform the user the platform is unsupported', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Unsupported platform (bar)'
+        );
+      });
+    });
+
+    describe('with an unsupported runtime', function() {
+      var prevValue;
+
+      beforeEach(function() {
+        prevValue = process.versions.modules;
+
+        Object.defineProperty(process.versions, 'modules', {
+          get: function () { return 'baz'; }
+        });
+      });
+
+      afterEach(function() {
+        process.versions.modules = prevValue;
+      });
+
+      it('should error', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Node Sass does not yet support your current environment'
+        );
+      });
+
+      it('should inform the user the runtime is unsupported', function() {
+        assert.throws(
+          function() { binding(etx); },
+          'Unsupported runtime (baz)'
+        );
+      });
+    });
+  });
+});