Look for Firefox in HKCU as well as HKLM (fix #73)

lib/utils.js

@@ -74,41 +74,41 @@ function normalizeBinary (binaryPath, platform, arch) {
     // Windows binary finding
     var appName = normalizeBinary.appNames[app + " on windows"];
 
-    // this is used when reading the registry goes wrong.
-    function fallBack () {
+    resolve(getPathToExe(Winreg.HKCU, appName).catch(function() {
+      return getPathToExe(Winreg.HKLM, appName);
+    }).catch(function() {
+      // Neither registry hive has the correct keys
       var programFilesVar = "ProgramFiles";
       if (arch === "(64)") {
         console.warn("You are using 32-bit version of Firefox on 64-bit versions of the Windows.\nSome features may not work correctly in this version. You should upgrade Firefox to the latest 64-bit version now!")
         programFilesVar = "ProgramFiles(x86)";
       }
-      resolve(path.join(process.env[programFilesVar], appName, "firefox.exe"));
-    }
+      return path.join(process.env[programFilesVar], appName, "firefox.exe");
+    }));
+  });
+}
+
+// Returns a promise to get Firefox's PathToExe from a registry hive
+function getPathToExe(hive, appName) {
+  const rootKey = path.join("\\Software\\Mozilla\\", appName);
+
+  return getRegistryValue(hive, rootKey, "CurrentVersion").then(function(version) {
+    return getRegistryValue(hive, path.join(rootKey, version, "Main"), "PathToExe");
+  });
+}
 
-    var rootKey = "\\Software\\Mozilla\\";
-    rootKey = path.join(rootKey, appName);
-
-    return when.promise(function(resolve, reject) {
-      var versionKey = new Winreg({
-        hive: Winreg.HKLM,
-        key: rootKey
-      });
-      versionKey.get("CurrentVersion", function(err, key) {
-        var isOk = key && !err;
-        return isOk ? resolve(key.value) : reject();
-      });
-    }).then(function(version) {
-      var mainKey = new Winreg({
-        hive: Winreg.HKLM,
-        key: path.join(rootKey, version, "Main")
-      });
-      mainKey.get("PathToExe", function(err, key) {
-        if (err) {
-          fallBack();
-          return;
-        }
-        resolve(key.value);
-      });
-    }, fallBack);
+// Returns a promise to get a single registry value
+function getRegistryValue(hive, key, name) {
+  return when.promise(function(resolve, reject) {
+    const registry = new Winreg({ hive, key });
+
+    registry.get(name, function(error, resultKey) {
+      if (resultKey && !error) {
+        resolve(resultKey.value);
+      } else {
+        reject(error);
+      }
+    });
   });
 }
 

test/run/test.utils.js

@@ -35,14 +35,70 @@ describe("lib/utils", function () {
       return;
     }
 
-    // see ./mock-winreg.js
     var expected = "fake\\binary\\path";
+
+    // see ./mock-winreg.js
+    // Only mock keys in HKLM (local machine) hive.
+    // This test case checks the basic functionality if the user does not have a newer version of
+    // Firefox installed meaning the HKCU keys are not present.
+    var winreg = function(options) {
+      this.get = function(_, fn) {
+        if (options.hive === winreg.HKLM) {
+          fn(null, {value: expected});
+        } else {
+          fn("Failed", null);
+        }
+      };
+    };
+    winreg.HKLM = "HKLM";
+
     var binary = sandbox.require("../../lib/utils", {
-      requires: {"winreg": function() {
-        this.get = function(_, fn) {
+      requires: { winreg }
+    }).normalizeBinary;
+
+    var promises = [
+      [null, "windows", "x86"],
+      [null, "windows", "x86_64"]
+    ].map(function(args) {
+      var promise = binary.apply(binary, args);
+      return promise.then(function(actual) {
+        expect(actual).to.be.equal(expected);
+      });
+    });
+    all(promises).then(done.bind(null, null), done);
+  });
+
+  it("normalizeBinary() prefers HKCU registry hive over HKLM on Windows", function(done) {
+    // Skip this test for now, to get Travis running.
+    if (!/win/i.test(os.platform)) {
+      done();
+      return;
+    }
+
+    // Provide different paths depending on hive.
+    // This test case checks that in order to find recent versions of Firefox, HKCU is tried
+    // before falling back on HKCU as in the test above.
+    var expected = "fake\\binary\\path";
+    var oldPath = "fake\\old\\binary\\path";
+
+    // see ./mock-winreg.js
+    var winreg = function(options) {
+      this.get = function(_, fn) {
+        if (options.hive === winreg.HKCU) {
           fn(null, {value: expected});
-        };
-      }}
+        } else if (options.hive === winreg.HKLM) {
+          fn(null, {value: oldPath});
+        } else {
+          fn("Failed", null);
+        }
+      };
+    };
+    // Differentiate hives
+    winreg.HKLM = "HKLM";
+    winreg.HKCU = "HKCU";
+
+    var binary = sandbox.require("../../lib/utils", {
+      requires: { winreg }
     }).normalizeBinary;
 
     var promises = [