1 files changed, 129 insertions, 0 deletions
diff --git a/test/unit/app/controllers/transactions/tx-state-history-helper-test.js b/test/unit/app/controllers/transactions/tx-state-history-helper-test.js
new file mode 100644
index 000000000..f4c3a6be1
--- /dev/null
+++ b/test/unit/app/controllers/transactions/tx-state-history-helper-test.js
@@ -0,0 +1,129 @@
+const assert = require('assert')
+const txStateHistoryHelper = require('../../../../../app/scripts/controllers/transactions/lib/tx-state-history-helper')
+const testVault = require('../../../../data/v17-long-history.json')
+
+describe ('Transaction state history helper', function () {
+
+  describe('#snapshotFromTxMeta', function () {
+    it('should clone deep', function () {
+      const input = {
+        foo: {
+          bar: {
+            bam: 'baz'
+          }
+        }
+      }
+      const output = txStateHistoryHelper.snapshotFromTxMeta(input)
+      assert('foo' in output, 'has a foo key')
+      assert('bar' in output.foo, 'has a bar key')
+      assert('bam' in output.foo.bar, 'has a bar key')
+      assert.equal(output.foo.bar.bam, 'baz', 'has a baz value')
+    })
+
+    it('should remove the history key', function () {
+      const input = { foo: 'bar', history: 'remembered' }
+      const output = txStateHistoryHelper.snapshotFromTxMeta(input)
+      assert(typeof output.history, 'undefined', 'should remove history')
+    })
+  })
+
+  describe('#migrateFromSnapshotsToDiffs', function () {
+    it('migrates history to diffs and can recover original values', function () {
+      testVault.data.TransactionController.transactions.forEach((tx, index) => {
+        const newHistory = txStateHistoryHelper.migrateFromSnapshotsToDiffs(tx.history)
+        newHistory.forEach((newEntry, index) => {
+          if (index === 0) {
+            assert.equal(Array.isArray(newEntry), false, 'initial history item IS NOT a json patch obj')
+          } else {
+            assert.equal(Array.isArray(newEntry), true, 'non-initial history entry IS a json patch obj')
+          }
+          const oldEntry = tx.history[index]
+          const historySubset = newHistory.slice(0, index + 1)
+          const reconstructedValue = txStateHistoryHelper.replayHistory(historySubset)
+          assert.deepEqual(oldEntry, reconstructedValue, 'was able to reconstruct old entry from diffs')
+        })
+      })
+    })
+  })
+
+  describe('#replayHistory', function () {
+    it('replaying history does not mutate the original obj', function () {
+      const initialState = { test: true, message: 'hello', value: 1 }
+      const diff1 = [{
+        "op": "replace",
+        "path": "/message",
+        "value": "haay",
+      }]
+      const diff2 = [{
+        "op": "replace",
+        "path": "/value",
+        "value": 2,
+      }]
+      const history = [initialState, diff1, diff2]
+
+      const beforeStateSnapshot = JSON.stringify(initialState)
+      const latestState = txStateHistoryHelper.replayHistory(history)
+      const afterStateSnapshot = JSON.stringify(initialState)
+
+      assert.notEqual(initialState, latestState, 'initial state is not the same obj as the latest state')
+      assert.equal(beforeStateSnapshot, afterStateSnapshot, 'initial state is not modified during run')
+    })
+  })
+
+  describe('#generateHistoryEntry', function () {
+
+    function generateHistoryEntryTest(note) {
+
+      const prevState = {
+        someValue: 'value 1',
+        foo: {
+          bar: {
+            bam: 'baz'
+          }
+        }
+      }
+
+      const nextState = {
+        newPropRoot: 'new property - root',
+        someValue: 'value 2',
+        foo: {
+          newPropFirstLevel: 'new property - first level',
+          bar: {
+            bam: 'baz'
+          }
+        }
+      }
+
+      const before = new Date().getTime()
+      const result = txStateHistoryHelper.generateHistoryEntry(prevState, nextState, note)
+      const after = new Date().getTime()
+
+      assert.ok(Array.isArray(result))
+      assert.equal(result.length, 3)
+
+      const expectedEntry1 = { op: 'add', path: '/foo/newPropFirstLevel', value: 'new property - first level' }
+      assert.equal(result[0].op, expectedEntry1.op)
+      assert.equal(result[0].path, expectedEntry1.path)
+      assert.equal(result[0].value, expectedEntry1.value)
+      assert.equal(result[0].value, expectedEntry1.value)
+      if (note) 
+        assert.equal(result[0].note, note)
+
+      assert.ok(result[0].timestamp >= before && result[0].timestamp <= after)
+
+      const expectedEntry2 = { op: 'replace', path: '/someValue', value: 'value 2' }
+      assert.deepEqual(result[1], expectedEntry2)
+
+      const expectedEntry3 = { op: 'add', path: '/newPropRoot', value: 'new property - root' }
+      assert.deepEqual(result[2], expectedEntry3)
+    }
+
+    it('should generate history entries', function () {
+      generateHistoryEntryTest()
+    })
+
+    it('should add note to first entry', function () {
+      generateHistoryEntryTest('custom note')
+    })    
+  })
+})
+\ No newline at end of file