Convert dashes in plugin names to underscores (#60)

For dashes to be preserved in a plugin's name, its executable name must convert
dashes to underscores.

For example a plugin named "foo-bar" would today be linked as:

    kubectl-foo-bar

therefore, it can only be invoked as:

    kubectl foo bar

However, linking the same plugin as:

    kubectl-foo_bar

allows plugin to be called as:

    kubectl foo-bar
    kubectl foo_bar

- convert OS detection pluginNameToBin() to explicit input for testability
- test pluginNameToBin().

Fixes #59.

pkg/installation/install.go

@@ -124,7 +124,7 @@ func Remove(p environment.KrewPaths, name string) error {
 }
 
 func createOrUpdateLink(binDir string, binary string, plugin string) error {
-	dst := filepath.Join(binDir, pluginNameToBin(plugin))
+	dst := filepath.Join(binDir, pluginNameToBin(plugin, isWindows()))
 
 	if err := removeLink(binDir, plugin); err != nil {
 		return fmt.Errorf("failed to remove old symlink, err: %v", err)
@@ -138,13 +138,13 @@ func createOrUpdateLink(binDir string, binary string, plugin string) error {
 	if err := os.Symlink(binary, dst); err != nil {
 		return fmt.Errorf("failed to create a symlink form %q to %q, err: %v", binDir, dst, err)
 	}
-	glog.V(2).Infof("Created symlink in %q", dst)
+	glog.V(2).Infof("Created symlink at %q", dst)
 
 	return nil
 }
 
 func removeLink(binDir string, plugin string) error {
-	dst := filepath.Join(binDir, pluginNameToBin(plugin))
+	dst := filepath.Join(binDir, pluginNameToBin(plugin, isWindows()))
 	if err := os.Remove(dst); err != nil && !os.IsNotExist(err) {
 		return fmt.Errorf("failed to remove the symlink in %q, err: %v", dst, err)
 	} else if err == nil {
@@ -153,10 +153,15 @@ func removeLink(binDir string, plugin string) error {
 	return nil
 }
 
-func pluginNameToBin(name string) string {
-	if runtime.GOOS == "windows" && !strings.HasSuffix(name, ".exe") {
+func isWindows() bool { return runtime.GOOS == "windows" }
+
+// pluginNameToBin creates the name of the symlink file for the plugin name.
+// It converts dashes to underscores.
+func pluginNameToBin(name string, isWindows bool) string {
+	name = strings.Replace(name, "-", "_", -1)
+	name = "kubectl-" + name
+	if isWindows {
 		name = name + ".exe"
 	}
-
-	return "kubectl-" + name
+	return name
 }

pkg/installation/install_test.go

@@ -123,3 +123,24 @@ func Test_createOrUpdateLink(t *testing.T) {
 		})
 	}
 }
+
+func Test_pluginNameToBin(t *testing.T) {
+
+	tests := []struct {
+		name      string
+		isWindows bool
+		want      string
+	}{
+		{"foo", false, "kubectl-foo"},
+		{"foo-bar", false, "kubectl-foo_bar"},
+		{"foo", true, "kubectl-foo.exe"},
+		{"foo-bar", true, "kubectl-foo_bar.exe"},
+	}
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			if got := pluginNameToBin(tt.name, tt.isWindows); got != tt.want {
+				t.Errorf("pluginNameToBin(%v, %v) = %v; want %v", tt.name, tt.isWindows, got, tt.want)
+			}
+		})
+	}
+}

pkg/installation/util.go

@@ -59,7 +59,7 @@ func findInstalledPluginVersion(installPath, binDir, pluginName string) (name st
 		return "", false, fmt.Errorf("the plugin name %q is not allowed", pluginName)
 	}
 	glog.V(3).Infof("Searching for installed versions of %s in %q", pluginName, binDir)
-	link, err := os.Readlink(filepath.Join(binDir, pluginNameToBin(pluginName)))
+	link, err := os.Readlink(filepath.Join(binDir, pluginNameToBin(pluginName, isWindows())))
 	if os.IsNotExist(err) {
 		return "", false, nil
 	} else if err != nil {