Classify Cardano pool IDs as bech32 or hex

src/utils/poolId.js

@@ -0,0 +1,39 @@
+import {bech32} from 'bech32'
+
+export const POOL_KEY_HASH_BYTES = 28
+export const HEX_POOL_ID_LENGTH = POOL_KEY_HASH_BYTES * 2
+
+export const classifyPoolId = (raw) => {
+  const value = typeof raw === 'string' ? raw.trim() : ''
+  if (!value) {
+    throw new Error('Pool ID is required')
+  }
+
+  const hexCandidate = value.replace(/^0x/i, '')
+  if (/^[0-9a-fA-F]+$/.test(hexCandidate)) {
+    if (hexCandidate.length !== HEX_POOL_ID_LENGTH) {
+      throw new Error('Hex pool key hash must be 56 characters')
+    }
+    return {format: 'hex', value: hexCandidate.toLowerCase()}
+  }
+
+  const bech32Candidate = value.toLowerCase()
+  if (bech32Candidate.startsWith('pool1')) {
+    let decoded
+    try {
+      decoded = bech32.decode(bech32Candidate)
+    } catch {
+      throw new Error('Bech32 pool ID is not a valid pool1… encoding')
+    }
+    if (decoded.prefix !== 'pool') {
+      throw new Error('Bech32 pool ID must use the pool prefix')
+    }
+    const payloadLength = bech32.fromWords(decoded.words).length
+    if (payloadLength !== POOL_KEY_HASH_BYTES) {
+      throw new Error('Bech32 pool ID must encode a 28-byte pool key hash')
+    }
+    return {format: 'bech32', value: bech32Candidate}
+  }
+
+  throw new Error('Pool ID must be a bech32 pool1… ID or a 56-character hex pool key hash')
+}

src/utils/poolId.test.js

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+import {Buffer} from 'buffer'
+import {bech32} from 'bech32'
+import {classifyPoolId, HEX_POOL_ID_LENGTH} from './poolId'
+
+const hex = 'deadbeef01234567890abcdef01234567890abcdef01234567890abc'
+const validBech32 = bech32.encode('pool', bech32.toWords(Buffer.from(hex, 'hex')))
+
+describe('classifyPoolId', () => {
+  it('rejects empty and whitespace-only input', () => {
+    expect(() => classifyPoolId('')).toThrow(/required/)
+    expect(() => classifyPoolId('   ')).toThrow(/required/)
+    expect(() => classifyPoolId(null)).toThrow(/required/)
+  })
+
+  it('accepts a 56-character hex pool key hash', () => {
+    expect(hex).toHaveLength(HEX_POOL_ID_LENGTH)
+    expect(classifyPoolId(hex)).toEqual({format: 'hex', value: hex})
+  })
+
+  it('strips a 0x prefix and lowercases hex', () => {
+    expect(classifyPoolId('0xDEADBEEF01234567890ABCDEF01234567890ABCDEF01234567890ABC')).toEqual({
+      format: 'hex',
+      value: hex,
+    })
+  })
+
+  it('rejects hex of the wrong length', () => {
+    expect(() => classifyPoolId('deadbeef')).toThrow(/56 characters/)
+    expect(() => classifyPoolId(`${'ab'.repeat(29)}`)).toThrow(/56 characters/)
+  })
+
+  it('accepts a valid pool1 bech32 ID', () => {
+    expect(classifyPoolId(`  ${validBech32.toUpperCase()}  `)).toEqual({format: 'bech32', value: validBech32})
+  })
+
+  it('rejects truncated, padded and checksum-invalid pool1 strings', () => {
+    expect(() => classifyPoolId('pool1qqqq')).toThrow(/valid pool1/)
+    expect(() => classifyPoolId(`${validBech32}q`)).toThrow(/valid pool1/)
+    expect(() => classifyPoolId('pool1qqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq')).toThrow(/valid pool1/)
+  })
+
+  it('rejects unrelated strings', () => {
+    expect(() => classifyPoolId('addr1xyz')).toThrow(/bech32 pool1/)
+  })
+})