fix: improve URL construction robustness and add edge case tests

- Use URL object manipulation for more robust path joining
- Handle edge cases: double slashes, query params, fragments
- Normalize paths to prevent duplicate slashes
- Add comprehensive test coverage for all URL scenarios

Author: daniel-lxs

src/api/providers/fetchers/__tests__/litellm.spec.ts

@@ -81,6 +81,90 @@ describe("getLiteLLMModels", () => {
 		})
 	})
 
+	it("handles base URLs with double slashes correctly", async () => {
+		const mockResponse = {
+			data: {
+				data: [],
+			},
+		}
+
+		mockedAxios.get.mockResolvedValue(mockResponse)
+
+		await getLiteLLMModels("test-api-key", "http://localhost:4000/litellm//")
+
+		expect(mockedAxios.get).toHaveBeenCalledWith("http://localhost:4000/litellm/v1/model/info", {
+			headers: {
+				Authorization: "Bearer test-api-key",
+				"Content-Type": "application/json",
+				...DEFAULT_HEADERS,
+			},
+			timeout: 5000,
+		})
+	})
+
+	it("handles base URLs with query parameters correctly", async () => {
+		const mockResponse = {
+			data: {
+				data: [],
+			},
+		}
+
+		mockedAxios.get.mockResolvedValue(mockResponse)
+
+		await getLiteLLMModels("test-api-key", "http://localhost:4000/litellm?key=value")
+
+		expect(mockedAxios.get).toHaveBeenCalledWith("http://localhost:4000/litellm/v1/model/info?key=value", {
+			headers: {
+				Authorization: "Bearer test-api-key",
+				"Content-Type": "application/json",
+				...DEFAULT_HEADERS,
+			},
+			timeout: 5000,
+		})
+	})
+
+	it("handles base URLs with fragments correctly", async () => {
+		const mockResponse = {
+			data: {
+				data: [],
+			},
+		}
+
+		mockedAxios.get.mockResolvedValue(mockResponse)
+
+		await getLiteLLMModels("test-api-key", "http://localhost:4000/litellm#section")
+
+		expect(mockedAxios.get).toHaveBeenCalledWith("http://localhost:4000/litellm/v1/model/info#section", {
+			headers: {
+				Authorization: "Bearer test-api-key",
+				"Content-Type": "application/json",
+				...DEFAULT_HEADERS,
+			},
+			timeout: 5000,
+		})
+	})
+
+	it("handles base URLs with port and no path correctly", async () => {
+		const mockResponse = {
+			data: {
+				data: [],
+			},
+		}
+
+		mockedAxios.get.mockResolvedValue(mockResponse)
+
+		await getLiteLLMModels("test-api-key", "http://localhost:4000")
+
+		expect(mockedAxios.get).toHaveBeenCalledWith("http://localhost:4000/v1/model/info", {
+			headers: {
+				Authorization: "Bearer test-api-key",
+				"Content-Type": "application/json",
+				...DEFAULT_HEADERS,
+			},
+			timeout: 5000,
+		})
+	})
+
 	it("successfully fetches and formats LiteLLM models", async () => {
 		const mockResponse = {
 			data: {

src/api/providers/fetchers/litellm.ts

@@ -24,7 +24,11 @@ export async function getLiteLLMModels(apiKey: string, baseUrl: string): Promise
 			headers["Authorization"] = `Bearer ${apiKey}`
 		}
 		// Use URL constructor to properly join base URL and path
-		const url = new URL("v1/model/info", baseUrl.endsWith("/") ? baseUrl : `${baseUrl}/`).href
+		// This approach handles all edge cases including paths, query params, and fragments
+		const urlObj = new URL(baseUrl)
+		// Normalize the pathname by removing trailing slashes and multiple slashes
+		urlObj.pathname = urlObj.pathname.replace(/\/+$/, "").replace(/\/+/g, "/") + "/v1/model/info"
+		const url = urlObj.href
 		// Added timeout to prevent indefinite hanging
 		const response = await axios.get(url, { headers, timeout: 5000 })
 		const models: ModelRecord = {}