@follow-app/client-sdk/src/client/base.test.ts

TypeScript client SDK for Follow RSS Server API

import { beforeEach, describe, expect, it, vi } from "vitest"

import { mockFetch } from "../test/setup"
import {
  FollowAPIError,
  FollowAuthError,
  FollowTimeoutError,
  FollowValidationError,
} from "../types/errors"
import { HttpClient } from "./base"

const createMockInterceptors = () => {
  return {
    processRequest: vi
      .fn()
      .mockImplementation((url, options) => ({ url, options })),
    processResponse: vi.fn().mockImplementation((response) => response),
    processError: vi.fn().mockImplementation(() => null),
    addRequestInterceptor: vi.fn(),
    addResponseInterceptor: vi.fn(),
    addErrorInterceptor: vi.fn(),
  }
}

// Mock the InterceptorManager at the top level
const mockInterceptors = createMockInterceptors()

vi.mock("./interceptors", () => ({
  InterceptorManager: vi.fn().mockImplementation(() => mockInterceptors),
}))

describe("HttpClient", () => {
  let client: HttpClient

  beforeEach(() => {
    // Reset all mock functions
    vi.clearAllMocks()

    // Reset mockInterceptors to fresh state
    Object.values(mockInterceptors).forEach((mockFn) => {
      if (typeof mockFn === "function" && "mockReset" in mockFn) {
        mockFn.mockReset()
      }
    })

    // Re-setup the default implementations
    mockInterceptors.processRequest.mockImplementation((url, options) => ({
      url,
      options,
    }))
    mockInterceptors.processResponse.mockImplementation((response) => response)
    mockInterceptors.processError.mockImplementation(() => null)

    client = new HttpClient({
      baseURL: "https://api.follow.is",
      timeout: 30000,
      headers: { "X-Test": "test" },
      credentials: "include",
    })
  })

  describe("Constructor", () => {
    it("should initialize with default configuration", () => {
      const defaultClient = new HttpClient({
        baseURL: "https://api.follow.is",
      })

      const config = defaultClient.getConfig()
      expect(config.baseURL).toBe("https://api.follow.is")
      expect(config.timeout).toBe(30000)
      expect(config.credentials).toBe("include")
      expect(config.headers).toEqual({})
    })

    it("should initialize with custom configuration", () => {
      const customClient = new HttpClient({
        baseURL: "https://custom.api.com",
        timeout: 60000,
        headers: { "Custom-Header": "value" },
        credentials: "same-origin",
      })

      const config = customClient.getConfig()
      expect(config.baseURL).toBe("https://custom.api.com")
      expect(config.timeout).toBe(60000)
      expect(config.headers).toEqual({ "Custom-Header": "value" })
      expect(config.credentials).toBe("same-origin")
    })

    it("should use custom fetch instance", () => {
      const customFetch = vi.fn()
      const customClient = new HttpClient({
        baseURL: "https://api.follow.is",
        fetch: customFetch,
      })

      expect(customClient.getConfig().fetch).toBe(customFetch)
    })
  })

  describe("URL Building", () => {
    it("should build URL without query parameters", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify({ code: 0, data: {} }), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await client.get("/test")

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "GET",
        }),
      )
    })

    it("should build URL with query parameters", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify({ code: 0, data: {} }), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await client.get("/test", {
        query: {
          param1: "value1",
          param2: 123,
          param3: true,
          // @ts-expect-error
          param4: undefined,
          // @ts-expect-error
          param5: null,
        },
      })

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test?param1=value1&param2=123&param3=true",
        expect.objectContaining({
          method: "GET",
        }),
      )
    })
  })

  describe("Request Methods", () => {
    it("should make GET request", async () => {
      const mockResponse = { code: 0, data: { id: 1, name: "test" } }
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.get("/test")

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "GET",
          headers: expect.objectContaining({
            "X-Test": "test",
          }),
        }),
      )
      expect(result).toEqual(mockResponse)
    })

    it("should make POST request with body", async () => {
      const mockResponse = { code: 0, data: { id: 1, created: true } }
      const requestBody = { name: "test", value: 123 }

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.post("/test", requestBody)

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "POST",
          body: JSON.stringify(requestBody),
          headers: expect.objectContaining({
            "Content-Type": "application/json",
            "X-Test": "test",
          }),
        }),
      )
      expect(result).toEqual(mockResponse)
    })

    it("should make PUT request", async () => {
      const mockResponse = { code: 0, data: { id: 1, updated: true } }
      const requestBody = { name: "updated", value: 456 }

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.put("/test", requestBody)

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "PUT",
          body: JSON.stringify(requestBody),
        }),
      )
      expect(result).toEqual(mockResponse)
    })

    it("should make PATCH request", async () => {
      const mockResponse = { code: 0, data: { id: 1, patched: true } }
      const requestBody = { value: 789 }

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.patch("/test", requestBody)

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "PATCH",
          body: JSON.stringify(requestBody),
        }),
      )
      expect(result).toEqual(mockResponse)
    })

    it("should make DELETE request", async () => {
      const mockResponse = { code: 0, data: { deleted: true } }

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.delete("/test")

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "DELETE",
        }),
      )
      expect(result).toEqual(mockResponse)
    })
  })

  describe("Response Handling", () => {
    it("should handle successful JSON response", async () => {
      const mockResponse = { code: 0, data: { success: true } }
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(mockResponse), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      const result = await client.get("/test")

      expect(result).toEqual(mockResponse)
    })

    it("should handle non-JSON response", async () => {
      const textResponse = "Plain text response"
      mockFetch.mockResolvedValueOnce(
        new Response(textResponse, {
          status: 200,
          headers: { "content-type": "text/plain" },
        }),
      )

      const result = await client.get("/test")

      expect(result).toBe(textResponse)
    })
  })

  describe("Error Handling", () => {
    it("should handle 401 authentication error", async () => {
      const errorResponse = { code: 401, message: "Unauthorized" }
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(errorResponse), {
          status: 401,
          headers: { "content-type": "application/json" },
        }),
      )

      await expect(client.get("/test")).rejects.toThrow(FollowAuthError)
    })

    it("should handle 400 validation error", async () => {
      const errorResponse = {
        code: 400,
        message: "Validation failed",
        data: [{ field: "name", message: "Required" }],
      }
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(errorResponse), {
          status: 400,
          headers: { "content-type": "application/json" },
        }),
      )

      await expect(client.get("/test")).rejects.toThrow(FollowValidationError)
    })

    it("should handle general API error", async () => {
      const errorResponse = { code: 500, message: "Internal Server Error" }
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify(errorResponse), {
          status: 500,
          headers: { "content-type": "application/json" },
        }),
      )

      await expect(client.get("/test")).rejects.toThrow(FollowAPIError)
    })

    it("should handle non-JSON error response", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response("Server Error", {
          status: 500,
          statusText: "Internal Server Error",
        }),
      )

      await expect(client.get("/test")).rejects.toThrow(FollowAPIError)
    })

    it("should handle network timeout", async () => {
      mockFetch.mockImplementation(() => {
        return new Promise((_, reject) => {
          setTimeout(() => {
            reject(new DOMException("Aborted", "AbortError"))
          }, 100)
        })
      })

      await expect(client.get("/test", { timeout: 50 })).rejects.toThrow(
        FollowTimeoutError,
      )
    })

    it("should handle custom signal abort", async () => {
      const controller = new AbortController()
      setTimeout(() => controller.abort(), 100)

      mockFetch.mockImplementation(() => {
        return new Promise((_, reject) => {
          setTimeout(() => {
            reject(new DOMException("Aborted", "AbortError"))
          }, 200)
        })
      })

      await expect(
        client.get("/test", { signal: controller.signal }),
      ).rejects.toThrow(FollowTimeoutError)
    })
  })

  describe("Interceptors Integration", () => {
    it("should process request interceptors", async () => {
      const modifiedUrl = "https://api.follow.is/modified"
      const modifiedOptions = {
        method: "POST",
        headers: { "X-Modified": "true" },
      }

      mockInterceptors.processRequest.mockResolvedValueOnce({
        url: modifiedUrl,
        options: modifiedOptions,
      })

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify({ code: 0, data: {} }), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await client.get("/test")

      expect(mockInterceptors.processRequest).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({ method: "GET" }),
      )
    })

    it("should process response interceptors", async () => {
      const originalResponse = new Response(
        JSON.stringify({ code: 0, data: {} }),
        {
          status: 200,
          headers: { "content-type": "application/json" },
        },
      )

      mockFetch.mockResolvedValueOnce(originalResponse)

      await client.get("/test")

      expect(mockInterceptors.processResponse).toHaveBeenCalledWith(
        originalResponse,
        "https://api.follow.is/test",
        expect.objectContaining({ method: "GET" }),
      )
    })

    it("should process error interceptors", async () => {
      const error = new Error("Test error")
      mockFetch.mockRejectedValueOnce(error)

      await expect(client.get("/test")).rejects.toThrow(error)

      expect(mockInterceptors.processError).toHaveBeenCalledWith(
        error,
        null,
        "https://api.follow.is/test",
        expect.objectContaining({ method: "GET" }),
      )
    })

    it("should process error interceptors with response object", async () => {
      const error = new Error("Test error")

      mockFetch.mockRejectedValueOnce(error)

      // Mock processError to verify it receives the response parameter
      mockInterceptors.processError.mockImplementation((err, res) => {
        expect(res).toBeNull() // Should be null when error occurs before response
        return err
      })

      await expect(client.get("/test")).rejects.toThrow(error)

      expect(mockInterceptors.processError).toHaveBeenCalledWith(
        error,
        null,
        "https://api.follow.is/test",
        expect.objectContaining({ method: "GET" }),
      )
    })

    it("should process error interceptors with response object when API returns error", async () => {
      const errorResponse = { code: 500, message: "Internal Server Error" }
      const response = new Response(JSON.stringify(errorResponse), {
        status: 500,
        headers: { "content-type": "application/json" },
      })

      mockFetch.mockResolvedValueOnce(response)

      // Mock processError to check if it would receive response in real scenario
      // Note: In current implementation, processError is called in catch block,
      // so response might not be available. This test documents the current behavior.

      await expect(client.get("/test")).rejects.toThrow(FollowAPIError)
    })

    it("should handle interceptor-modified errors", async () => {
      const originalError = new Error("Original error")
      const modifiedError = new Error("Modified error")

      mockFetch.mockRejectedValueOnce(originalError)
      mockInterceptors.processError.mockResolvedValueOnce(modifiedError)

      await expect(client.get("/test")).rejects.toThrow(modifiedError)
    })

    it("should suppress errors when interceptor returns undefined", async () => {
      const originalError = new Error("Original error")

      mockFetch.mockRejectedValueOnce(originalError)
      // Return undefined to suppress the error
      mockInterceptors.processError.mockResolvedValueOnce(void 0)

      // Should not throw since interceptor suppressed the error
      await expect(client.get("/test")).rejects.toThrow(originalError)
    })
  })

  describe("Configuration Management", () => {
    it("should update configuration", () => {
      const newConfig = {
        baseURL: "https://new.api.com",
        timeout: 60000,
        headers: { "X-New": "header" },
      }

      client.setConfig(newConfig)

      const config = client.getConfig()
      expect(config.baseURL).toBe("https://new.api.com")
      expect(config.timeout).toBe(60000)
      // setConfig replaces headers entirely, not merges
      expect(config.headers).toEqual({ "X-New": "header" })
    })

    it("should set headers", () => {
      const newHeaders = { "X-Custom": "value", "Authorization": "Bearer token" }

      client.setHeaders(newHeaders)

      const config = client.getConfig()
      expect(config.headers).toEqual({
        "X-Test": "test",
        "X-Custom": "value",
        "Authorization": "Bearer token",
      })
    })

    it("should set custom fetch instance", () => {
      const customFetch = vi.fn()

      client.setFetch(customFetch)

      const config = client.getConfig()
      expect(config.fetch).toBe(customFetch)
    })

    it("should get interceptor manager", () => {
      const interceptors = client.getInterceptors()
      expect(interceptors).toBe(mockInterceptors)
    })
  })

  describe("Request Options", () => {
    it("should handle custom headers in request", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify({ code: 0, data: {} }), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await client.get("/test", {
        headers: { "X-Custom": "request-header" },
      })

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          headers: expect.objectContaining({
            "X-Test": "test",
            "X-Custom": "request-header",
          }),
        }),
      )
    })

    it("should handle custom timeout in request", async () => {
      mockFetch.mockImplementation(() => {
        return new Promise((_, reject) => {
          // Simulate timeout by rejecting with AbortError after delay
          setTimeout(() => {
            reject(new DOMException("Aborted", "AbortError"))
          }, 100)
        })
      })

      await expect(client.get("/test", { timeout: 50 })).rejects.toThrow(
        FollowTimeoutError,
      )
    })

    it("should handle form data body", async () => {
      const formData = new FormData()
      formData.append("file", "test content")

      mockFetch.mockResolvedValueOnce(
        new Response(JSON.stringify({ code: 0, data: {} }), {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await client.request("/test", {
        method: "POST",
        body: formData,
      })

      expect(mockFetch).toHaveBeenCalledWith(
        "https://api.follow.is/test",
        expect.objectContaining({
          method: "POST",
          body: formData,
        }),
      )
    })
  })

  describe("Edge Cases", () => {
    it("should handle empty response", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response("", {
          status: 200,
        }),
      )

      const result = await client.get("/test")

      expect(result).toBe("")
    })

    it("should handle malformed JSON response", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response("{ invalid json", {
          status: 200,
          headers: { "content-type": "application/json" },
        }),
      )

      await expect(client.get("/test")).rejects.toThrow()
    })

    it("should handle response without content-type", async () => {
      mockFetch.mockResolvedValueOnce(
        new Response("Plain response", {
          status: 200,
        }),
      )

      const result = await client.get("/test")

      expect(result).toBe("Plain response")
    })

    it("should handle concurrent requests", async () => {
      // Create a new Response for each call to avoid "Body already read" error
      mockFetch.mockImplementation(() =>
        Promise.resolve(
          new Response(JSON.stringify({ code: 0, data: {} }), {
            status: 200,
            headers: { "content-type": "application/json" },
          }),
        ),
      )

      const promises = Array.from({ length: 10 }, (_, i) =>
        client.get(`/test${i}`))

      const results = await Promise.all(promises)

      expect(results).toHaveLength(10)
      expect(mockFetch).toHaveBeenCalledTimes(10)
    })
  })
})