For IPFS, for example, you would typically run an IPFS node on your machine that communicates directly with the IPFS network, then configure your browser to use that node for all IPFS, and then all IPFS interactions would happen by making HTTP requests to the node from your web app. // Import MockIPFS and create a fake node: import * as MockIPFS from 'mockipfs'; const mockNode = MockIPFS.getLocal(); describe("Your tests", () => { // Start & stop your mock node to reset state between tests beforeEach(() => mockNode.start()); afterEach(() => mockNode.stop()); it("can mock & query IPFS interactions", async () => { // Define a rule to mock out this content: const ipfsPath = "/ipfs/Qme7ss3ARVgxv6rXqVPiikMJ8u2NLgmgszg13pYrDKEoiu"; const mockedContent = await…