diff --git a/test/TemplatedPathPlugin.unittest.js b/test/TemplatedPathPlugin.unittest.js
new file mode 100644
index 000000000..80cf16613
--- /dev/null
+++ b/test/TemplatedPathPlugin.unittest.js
@@ -0,0 +1,143 @@
+"use strict";
+
+const TemplatedPathPlugin = require("../lib/TemplatedPathPlugin");
+
+describe("TemplatedPathPlugin", () => {
+	describe("hash should be non-numeric", () => {
+		// Move capturedPathReplacer to higher scope to be accessible in all describe blocks
+		let capturedPathReplacer;
+
+		// Set up capturedPathReplacer for all tests
+		beforeEach(() => {
+			const mockCompilation = {
+				hooks: {
+					assetPath: {
+						tap: jest.fn((pluginName, pathReplacerFn) => {
+							capturedPathReplacer = pathReplacerFn;
+						})
+					}
+				}
+			};
+
+			const mockCompiler = {
+				hooks: {
+					compilation: {
+						tap: jest.fn((pluginName, compilationFn) => {
+							compilationFn(mockCompilation);
+						})
+					}
+				}
+			};
+
+			// Apply the plugin to capture the path replacer function
+			const plugin = new TemplatedPathPlugin();
+			plugin.apply(mockCompiler);
+		});
+
+		it("should prevent numeric-only chunkhash in filename templates", () => {
+			const mockChunk = {
+				id: "test-chunk",
+				name: "test-chunk",
+				renderedHash: "123456789012345678901234567890",
+				hash: "123456789012345678901234567890"
+			};
+
+			const pathData = {
+				chunk: mockChunk,
+				chunkGraph: {},
+				runtime: undefined
+			};
+
+			const result = capturedPathReplacer("[name].[chunkhash:8].js", pathData);
+
+			// Should convert numeric-only hash to include letter prefix
+			expect(result).toBe("test-chunk.b2345678.js");
+			expect(result).toMatch(/^test-chunk\.[a-f]\d{7}\.js$/);
+			expect(result).not.toMatch(/^test-chunk\.\d{8}\.js$/);
+		});
+
+		it("should prevent numeric-only contenthash in filename templates", () => {
+			const mockChunk = {
+				id: "content-chunk",
+				name: "content-chunk",
+				renderedHash: "abc123def456",
+				hash: "abc123def456",
+				contentHash: {
+					javascript: "987654321098765432109876543210"
+				}
+			};
+
+			const pathData = {
+				chunk: mockChunk,
+				contentHashType: "javascript",
+				chunkGraph: {},
+				runtime: undefined
+			};
+
+			const result = capturedPathReplacer(
+				"[name].[contenthash:6].js",
+				pathData
+			);
+
+			// Should convert numeric-only hash to include letter prefix
+			expect(result).toBe("content-chunk.d87654.js");
+			expect(result).toMatch(/^content-chunk\.[a-f]\d{5}\.js$/);
+			expect(result).not.toMatch(/^content-chunk\.\d{6}\.js$/);
+		});
+
+		it("should prevent numeric-only fullhash in filename templates", () => {
+			const pathData = {
+				hash: "111111111111111111111111111111",
+				chunkGraph: {},
+				runtime: undefined
+			};
+
+			const result = capturedPathReplacer("bundle.[fullhash:10].js", pathData);
+
+			// Should convert numeric-only hash to include letter prefix
+			expect(result).toBe("bundle.b111111111.js");
+			expect(result).toMatch(/^bundle\.[a-f]\d{9}\.js$/);
+			expect(result).not.toMatch(/^bundle\.\d{10}\.js$/);
+		});
+
+		it("should preserve alphanumeric hashes unchanged", () => {
+			const mockChunk = {
+				id: "mixed-chunk",
+				name: "mixed-chunk",
+				renderedHash: "abc123def456ghi789jkl012mno345",
+				hash: "abc123def456ghi789jkl012mno345"
+			};
+
+			const pathData = {
+				chunk: mockChunk,
+				chunkGraph: {},
+				runtime: undefined
+			};
+
+			const result = capturedPathReplacer("[name].[chunkhash:8].js", pathData);
+
+			// Should preserve original hash since it contains non-numeric chars
+			expect(result).toBe("mixed-chunk.abc123de.js");
+		});
+
+		it("should handle zero-length hash parameter", () => {
+			const mockChunk = {
+				id: "zero-chunk",
+				name: "zero-chunk",
+				renderedHash: "123456789012345678901234567890",
+				hash: "123456789012345678901234567890"
+			};
+
+			const pathData = {
+				chunk: mockChunk,
+				chunkGraph: {},
+				runtime: undefined
+			};
+
+			const result = capturedPathReplacer("[name].[chunkhash:0].js", pathData);
+
+			// When length is 0, it's treated as falsy and returns the full hash
+			expect(result).toBe("zero-chunk.123456789012345678901234567890.js");
+		});
+	});
+});