Added unit tests for context.ts

src/utils/context.spec.ts

@@ -0,0 +1,51 @@
+import { Context } from './context'
+import { VoidSigner } from '@ethersproject/abstract-signer'
+import { Provider } from '@ethersproject/providers'
+
+test('Context: update chainId', async () => {
+  const context = new Context(1, {})
+  let chainId = await context.chainId
+  expect(chainId).toEqual(1)
+
+  // works
+  chainId = await context.updateChainId(4)
+  expect(chainId).toEqual(4)
+})
+
+test('Context: update chainId fails', () => {
+  const context = new Context(1, {})
+
+  expect(() => {
+    context.updateChainId(123)
+  }).toThrow('Invalid chainId: 123')
+})
+
+test('Context: get chainId from provider - matches context', async () => {
+  const mockProvider = jest.fn<Provider, []>()
+  const provider = new mockProvider()
+  provider.getNetwork = jest.fn(async () => ({ chainId: 1, name: 'bla' }))
+
+  const signer = new VoidSigner('', provider)
+
+  const context = new Context(1, { signer })
+
+  const chainId = await context.chainId
+
+  expect(chainId).toEqual(1)
+  expect(provider.getNetwork).toHaveBeenCalledTimes(1)
+})
+
+test('Context: get chainId from provider - differs from context', async () => {
+  const mockProvider = jest.fn<Provider, []>()
+  const provider = new mockProvider()
+  provider.getNetwork = jest.fn(async () => ({ chainId: 100, name: 'bla' }))
+
+  const signer = new VoidSigner('', provider)
+
+  const context = new Context(1, { signer })
+
+  const chainId = await context.chainId
+
+  expect(chainId).toEqual(100)
+  expect(provider.getNetwork).toHaveBeenCalledTimes(1)
+})