diff --git a/claudetool/bashkit/bashkit_test.go b/claudetool/bashkit/bashkit_test.go
new file mode 100644
index 0000000..8bcdd8f
--- /dev/null
+++ b/claudetool/bashkit/bashkit_test.go
@@ -0,0 +1,109 @@
+package bashkit
+
+import (
+	"strings"
+	"testing"
+)
+
+func TestCheck(t *testing.T) {
+	tests := []struct {
+		name     string
+		script   string
+		wantErr  bool
+		errMatch string // string to match in error message, if wantErr is true
+	}{
+		{
+			name:     "valid script",
+			script:   "echo hello world",
+			wantErr:  false,
+			errMatch: "",
+		},
+		{
+			name:     "invalid syntax",
+			script:   "echo 'unterminated string",
+			wantErr:  false, // As per implementation, syntax errors are not flagged
+			errMatch: "",
+		},
+		{
+			name:     "git config user.name",
+			script:   "git config user.name 'John Doe'",
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name:     "git config user.email",
+			script:   "git config user.email 'john@example.com'",
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name:     "git config with flag user.name",
+			script:   "git config --global user.name 'John Doe'",
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name:     "git config with other setting",
+			script:   "git config core.editor vim",
+			wantErr:  false,
+			errMatch: "",
+		},
+		{
+			name:     "git without config",
+			script:   "git commit -m 'Add feature'",
+			wantErr:  false,
+			errMatch: "",
+		},
+		{
+			name:     "multiline script with proper escaped newlines",
+			script:   "echo 'Setting up git...' && git config user.name 'John Doe' && echo 'Done!'",
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name: "multiline script with backticks",
+			script: `echo 'Setting up git...'
+git config user.name 'John Doe'
+echo 'Done!'`,
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name:     "git config with variable",
+			script:   "NAME='John Doe'\ngit config user.name $NAME",
+			wantErr:  true,
+			errMatch: "changing git config username/email is not allowed",
+		},
+		{
+			name:     "only git command",
+			script:   "git",
+			wantErr:  false,
+			errMatch: "",
+		},
+		{
+			name:     "read git config",
+			script:   "git config user.name",
+			wantErr:  false,
+			errMatch: "",
+		},
+		{
+			name:     "commented git config",
+			script:   "# git config user.name 'John Doe'",
+			wantErr:  false,
+			errMatch: "",
+		},
+	}
+
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			err := Check(tc.script)
+			if (err != nil) != tc.wantErr {
+				t.Errorf("Check() error = %v, wantErr %v", err, tc.wantErr)
+				return
+			}
+			if tc.wantErr && err != nil && !strings.Contains(err.Error(), tc.errMatch) {
+				t.Errorf("Check() error message = %v, want containing %v", err, tc.errMatch)
+			}
+		})
+	}
+}