fix: fence inter-mint transfer operations

src/lnurlcash/ops.transfer.cases.ts

@@ -0,0 +1,136 @@
+import {describe, expect, it} from 'vitest'
+import {createMockMint} from 'lnurlcash-conformance/mock-mint'
+import {noteK1} from 'lnurlcash-kit'
+
+import {transferBetweenMints} from './ops'
+import {requiredValue} from './test-utils'
+import {expectBurned, makeBearer, mint, secret, settleWhenRequested} from './ops.testHarness'
+
+describe('transferBetweenMints', () => {
+  const fastPoll = {intervalMs: 10, intervalCapMs: 50, maxWaitMs: 5_000}
+
+  it('moves value to another mint: melt at source, claim + rotate at target', async () => {
+    const source = await mint()
+    const target = await mint({testHooks: true})
+    const k1 = secret('40')
+    const bearer = await makeBearer(source, k1, 21_000)
+    const pending = transferBetweenMints([bearer], 21_000, `mint@127.0.0.1:${target.port}`, {
+      poll: fastPoll,
+    })
+    const preimage = await settleWhenRequested(target)
+    const result = await pending
+    expect(result.outcome).toBe('settled')
+    expect(result.invoice).toMatch(/^lnbc/)
+    expect(result.quote).toEqual({
+      requestedMsat: 21_000,
+      grossMsat: 21_000,
+      targetMintFeeMsat: 0,
+      sourceMeltFeeReserveMsat: 0,
+    })
+    expect(result.sourceServer).not.toBe(result.targetServer)
+    await expectBurned(source, k1)
+    const claimed = requiredValue(result.mintedAtTarget)
+    expect(claimed.rotated).toBe(true)
+    expect(claimed.note.amount).toBe(21_000)
+    expect(claimed.note.verified).toBe(true)
+    expect(target.state.noteState(preimage)).toBe('burned')
+    const newK1 = requiredValue(noteK1(claimed.note.url))
+    expect(newK1).not.toBe(preimage)
+    expect(target.state.noteState(newK1)).toBe('outstanding')
+  })
+
+  it('refuses an amount no source mint can cover', async () => {
+    const source = await mint()
+    const target = await mint()
+    const k1 = secret('41')
+    const bearer = await makeBearer(source, k1, 5_000)
+    await expect(
+      transferBetweenMints([bearer], 50_000, `mint@127.0.0.1:${target.port}`),
+    ).rejects.toThrow(/enough/)
+    expect(source.state.noteState(k1)).toBe('outstanding')
+  })
+
+  it('rejects a transfer onto the mint the notes are already on', async () => {
+    const instance = await mint()
+    const k1 = secret('42')
+    const bearer = await makeBearer(instance, k1, 21_000)
+    await expect(
+      transferBetweenMints([bearer], 21_000, `mint@127.0.0.1:${instance.port}`),
+    ).rejects.toThrow(/different target/)
+    expect(instance.state.noteState(k1)).toBe('outstanding')
+  })
+
+  it('moves nothing when the target mint is unreachable', async () => {
+    const source = await mint()
+    const dead = await createMockMint()
+    const deadAddress = `mint@127.0.0.1:${dead.port}`
+    await dead.close()
+    const k1 = secret('43')
+    const bearer = await makeBearer(source, k1, 50_000)
+    await expect(transferBetweenMints([bearer], 21_000, deadAddress)).rejects.toThrow()
+    expect(source.state.noteState(k1)).toBe('outstanding')
+  })
+
+  it('recovers from a melt whose answer was lost once the target invoice settles', async () => {
+    const source = await mint({unconfirmedMutation: true})
+    const target = await mint({testHooks: true})
+    const k1 = secret('44')
+    const bearer = await makeBearer(source, k1, 21_000)
+    const pending = transferBetweenMints([bearer], 21_000, `mint@127.0.0.1:${target.port}`, {
+      poll: fastPoll,
+    })
+    await settleWhenRequested(target)
+    const result = await pending
+    expect(result.outcome).toBe('settled')
+    await expectBurned(source, k1)
+    expect(result.mintedAtTarget?.note.amount).toBe(21_000)
+    expect(result.mintedAtTarget?.rotated).toBe(true)
+  })
+
+  it('surfaces the claimable preimage note when the claim fails after a settled melt', async () => {
+    const source = await mint()
+    const target = await mint({testHooks: true, echoWrongK1: true})
+    const k1 = secret('45')
+    const bearer = await makeBearer(source, k1, 21_000)
+    const pending = transferBetweenMints([bearer], 21_000, `mint@127.0.0.1:${target.port}`, {
+      poll: fastPoll,
+    })
+    const preimage = await settleWhenRequested(target)
+    const result = await pending
+    expect(result.outcome).toBe('settled-claim-failed')
+    await expectBurned(source, k1)
+    const note = requiredValue(result.claimMaterial?.note)
+    expect(noteK1(note.url)).toBe(preimage)
+    expect(note.verified).toBe(false)
+    expect(note.amount).toBe(21_000)
+    expect(result.claimMaterial?.withdrawLink).toContain(`${target.port}`)
+  })
+
+  it('grosses the carve up for the target mint fee, refusing when only the net is covered', async () => {
+    const source = await mint()
+    const target = await mint({baseFeeMsat: 1_000, feePpm: 2_000})
+    const k1 = secret('46')
+    const bearer = await makeBearer(source, k1, 100_000)
+    await expect(
+      transferBetweenMints([bearer], 100_000, `mint@127.0.0.1:${target.port}`),
+    ).rejects.toThrow(/enough/)
+    expect(source.state.noteState(k1)).toBe('outstanding')
+  })
+
+  it('restores the source note, re-secured, when the melt fails', async () => {
+    const source = await mint({meltAlwaysFails: true})
+    const target = await mint({testHooks: true})
+    const k1 = secret('47')
+    const bearer = await makeBearer(source, k1, 21_000)
+    const result = await transferBetweenMints([bearer], 21_000, `mint@127.0.0.1:${target.port}`, {
+      poll: {intervalMs: 10, intervalCapMs: 20, maxWaitMs: 300},
+    })
+    expect(result.outcome).toBe('failed-funds-returned')
+    expect(result.mintedAtTarget).toBeUndefined()
+    expect(source.state.noteState(k1)).toBe('burned')
+    const returnedK1 = requiredValue(noteK1(result.carve.note.url))
+    expect(returnedK1).not.toBe(k1)
+    expect(source.state.noteState(returnedK1)).toBe('outstanding')
+    expect(result.carve.note.amount).toBe(21_000)
+  })
+})