diff --git a/src/test/suite/configuration.test.ts b/src/test/suite/configuration.test.ts
new file mode 100644
index 0000000000..4311640edc
--- /dev/null
+++ b/src/test/suite/configuration.test.ts
@@ -0,0 +1,59 @@
+import assert from "assert";
+import * as vscode from "vscode";
+import { Configuration } from "../../configuration/configuration";
+
+interface MockWorkspaceConfig {
+  get(key: string): unknown;
+}
+
+suite("Configuration", () => {
+  test("validates killRingMax configuration", () => {
+    const config = Configuration.instance;
+    const mockConfig: MockWorkspaceConfig = {
+      get: (key: string): number | undefined => {
+        if (key === "killRingMax") return -1;
+        return undefined;
+      },
+    };
+
+    // Mock workspace configuration
+    const originalGetConfiguration = vscode.workspace.getConfiguration;
+    vscode.workspace.getConfiguration = (): vscode.WorkspaceConfiguration =>
+      mockConfig as vscode.WorkspaceConfiguration;
+
+    try {
+      // Access configuration to trigger validation
+      assert.throws(() => {
+        void config.killRingMax;
+      }, /killRingMax must be a positive integer/);
+    } finally {
+      // Restore mock
+      vscode.workspace.getConfiguration = originalGetConfiguration;
+    }
+  });
+
+  test("validates debug configuration", () => {
+    const config = Configuration.instance;
+    const mockConfig: MockWorkspaceConfig = {
+      get: (key: string): Record<string, unknown> | undefined => {
+        if (key === "debug") return { silent: "not-a-boolean", loggingLevelForAlert: "invalid" };
+        return undefined;
+      },
+    };
+
+    // Mock workspace configuration
+    const originalGetConfiguration = vscode.workspace.getConfiguration;
+    vscode.workspace.getConfiguration = (): vscode.WorkspaceConfiguration =>
+      mockConfig as vscode.WorkspaceConfiguration;
+
+    try {
+      // Access configuration to trigger validation
+      assert.throws(() => {
+        void config.debug;
+      }, /debug.silent must be a boolean/);
+    } finally {
+      // Restore mock
+      vscode.workspace.getConfiguration = originalGetConfiguration;
+    }
+  });
+});
diff --git a/src/test/suite/kill-ring.test.ts b/src/test/suite/kill-ring.test.ts
index 97d24b7f4d..bfbbc505d1 100644
--- a/src/test/suite/kill-ring.test.ts
+++ b/src/test/suite/kill-ring.test.ts
@@ -67,4 +67,29 @@ suite("KillRing", () => {
     assert.strictEqual(killRing.popNext(), undefined);
     assert.strictEqual(killRing.popNext(), undefined);
   });
+
+  test("handles invalid push data gracefully", () => {
+    const killRing = new KillRing(3);
+
+    // Test pushing null
+    assert.doesNotThrow(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      killRing.push(null as any); // Testing error handling
+    });
+    assert.strictEqual(killRing.getTop(), undefined);
+
+    // Test pushing undefined
+    assert.doesNotThrow(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      killRing.push(undefined as any); // Testing error handling
+    });
+    assert.strictEqual(killRing.getTop(), undefined);
+
+    // Test pushing invalid entity
+    assert.doesNotThrow(() => {
+      // eslint-disable-next-line @typescript-eslint/no-explicit-any
+      killRing.push({ invalid: "entity" } as any); // Testing error handling
+    });
+    assert.strictEqual(killRing.getTop(), undefined);
+  });
 });