remove deps, add simple hashFunction for example and tests.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "fixed-merkle-tree",
-  "version": "0.6.1",
+  "version": "0.7.0",
   "description": "Fixed depth merkle tree implementation with sequential inserts",
   "repository": "https://github.com/tornadocash/fixed-merkle-tree.git",
   "main": "lib/index.js",
@@ -8,7 +8,9 @@
   "scripts": {
     "test": "ts-mocha 'test/*.spec.ts'",
     "build": "tsc",
-    "lint": "eslint ."
+    "clean": "rm -rf lib/",
+    "prepare": "npm run clean && npm run build",
+    "lint": "eslint src"
   },
   "keywords": [
     "merkle",
@@ -20,9 +22,7 @@
   "files": [
     "src/*"
   ],
-  "dependencies": {
-    "circomlib": "git+https://github.com/tornadocash/circomlib.git#5beb6aee94923052faeecea40135d45b6ce6172c"
-  },
+  "dependencies": {},
   "devDependencies": {
     "@types/expect": "^24.3.0",
     "@types/mocha": "^9.1.0",

src/index.ts

@@ -1,9 +1,6 @@
-import { mimcsponge } from 'circomlib'
+import simpleHash from './simpleHash'
 
-// keccak256("tornado") % BN254_FIELD_SIZE
-const DEFAULT_ZERO = '21663839004416932945382355908790599225266501822907911457504978515578255421292'
-
-const defaultHash = (left: Element, right: Element): string => mimcsponge.multiHash([BigInt(left), BigInt(right)]).toString()
+const defaultHash = (left: Element, right: Element): string => simpleHash([left, right])
 
 export default class MerkleTree {
   get layers(): Array<Element[]> {
@@ -23,7 +20,7 @@ export default class MerkleTree {
 
   constructor(levels: number, elements: Element[] = [], {
     hashFunction = defaultHash,
-    zeroElement = DEFAULT_ZERO,
+    zeroElement = 0,
   }: MerkleTreeOptions = {}) {
     this.levels = levels
     this.capacity = 2 ** levels
@@ -131,30 +128,30 @@ export default class MerkleTree {
    * @param {number} index Leaf index to generate path for
    * @returns {{pathElements: Object[], pathIndex: number[]}} An object containing adjacent elements and left-right index
    */
-  path(index: Element) {
+  path(index: Element): ProofPath {
     if (isNaN(Number(index)) || index < 0 || index >= this._layers[0].length) {
       throw new Error('Index out of bounds: ' + index)
     }
     let elIndex = +index
     const pathElements: Element[] = []
     const pathIndices: number[] = []
-    const layerIndices: number[] = []
+    const pathPositions: number [] = []
     for (let level = 0; level < this.levels; level++) {
       pathIndices[level] = elIndex % 2
       const leafIndex = elIndex ^ 1
       if (leafIndex < this._layers[level].length) {
         pathElements[level] = this._layers[level][leafIndex]
-        layerIndices[level] = leafIndex
+        pathPositions[level] = leafIndex
       } else {
         pathElements[level] = this._zeros[level]
-        layerIndices[level] = 0
+        pathPositions[level] = 0
       }
       elIndex >>= 1
     }
     return {
       pathElements,
       pathIndices,
-      layerIndices,
+      pathPositions,
     }
   }
 
@@ -268,6 +265,9 @@ export type SerializedTreeState = {
   _zeros: Array<Element>,
   _layers: Array<Element[]>
 }
-export type Mimcsponge = {
-  multiHash: (arr: BigInt[], key?: Element, numOutputs?) => string
+
+export type ProofPath = {
+  pathElements: Element[],
+  pathIndices: number[],
+  pathPositions: number[],
 }

src/simpleHash.ts

@@ -0,0 +1,20 @@
+/***
+ * This is insecure hash function, just for example only
+ * @param data
+ * @param seed
+ * @param hashLength
+ */
+
+function simpleHash<T>(data: T[], seed?: number, hashLength = 40): string {
+  const str = data.join('')
+  let i, l,
+    hval = seed ?? 0x811c9dcc5
+  for (i = 0, l = str.length; i < l; i++) {
+    hval ^= str.charCodeAt(i)
+    hval += (hval << 1) + (hval << 4) + (hval << 6) + (hval << 8) + (hval << 24)
+  }
+  const hash = (hval >>> 0).toString(16)
+  return BigInt('0x' + hash.padEnd(hashLength - (hash.length - 1), '0')).toString(10)
+}
+
+export default simpleHash

test/merkleTree.spec.ts

@@ -8,22 +8,22 @@ describe('MerkleTree', () => {
 
     it('should have correct zero root', () => {
       const tree = new MerkleTree(10, [])
-      return should().equal(tree.root(), '14030416097908897320437553787826300082392928432242046897689557706485311282736')
+      return should().equal(tree.root(), '3060353338620102847451617558650138132480')
     })
 
     it('should have correct 1 element root', () => {
       const tree = new MerkleTree(10, [1])
-      should().equal(tree.root(), '8423266420989796135179818298985240707844287090553672312129988553683991994663')
+      should().equal(tree.root(), '4059654748770657324723044385589999697920')
     })
 
     it('should have correct even elements root', () => {
       const tree = new MerkleTree(10, [1, 2])
-      should().equal(tree.root(), '6632020347849276860492323008882350357301732786233864934344775324188835172576')
+      should().equal(tree.root(), '3715471817149864798706576217905179918336')
     })
 
     it('should have correct odd elements root', () => {
       const tree = new MerkleTree(10, [1, 2, 3])
-      should().equal(tree.root(), '13605252518346649016266481317890801910232739395710162921320863289825142055129')
+      should().equal(tree.root(), '5199180210167621115778229238102210117632')
     })
 
     it('should be able to create a full tree', () => {
@@ -40,19 +40,19 @@ describe('MerkleTree', () => {
     it('should insert into empty tree', () => {
       const tree = new MerkleTree(10)
       tree.insert(42)
-      should().equal(tree.root(), '5305397050004975530787056746976521882221645950652996479084366175595194436378')
+      should().equal(tree.root(), '750572848877730275626358141391262973952')
     })
 
     it('should insert into odd tree', () => {
       const tree = new MerkleTree(10, [1])
       tree.insert(42)
-      should().equal(tree.root(), '4732716818150428188641303198013632061441036732749853605989871103991103096471')
+      should().equal(tree.root(), '5008383558940708447763798816817296703488')
     })
 
     it('should insert into even tree', () => {
       const tree = new MerkleTree(10, [1, 2])
       tree.insert(42)
-      should().equal(tree.root(), '6204016789747878948181936326719724987136198810274146408545977300318734508764')
+      should().equal(tree.root(), '5005864318873356880627322373636156817408')
     })
 
     it('should insert last element', () => {
@@ -71,7 +71,7 @@ describe('MerkleTree', () => {
     it('should work', () => {
       const tree = new MerkleTree(10, [1, 2, 3])
       tree.bulkInsert([4, 5, 6])
-      should().equal(tree.root(), '10132905325673518287563057607527946096399700874345297651940963130460267058606')
+      should().equal(tree.root(), '4066635800770511602067209448381558554624')
     })
 
     it('should give the same result as sequental inserts', () => {
@@ -116,31 +116,31 @@ describe('MerkleTree', () => {
     it('should update first element', () => {
       const tree = new MerkleTree(10, [1, 2, 3, 4, 5])
       tree.update(0, 42)
-      should().equal(tree.root(), '153077538697962715163231177553585573790587443799974092612333826693999310199')
+      should().equal(tree.root(), '3884161948856565981263417078389340635136')
     })
 
     it('should update last element', () => {
       const tree = new MerkleTree(10, [1, 2, 3, 4, 5])
       tree.update(4, 42)
-      should().equal(tree.root(), '1955192134603843666100093417117434845771298375724087600313714421260719033775')
+      should().equal(tree.root(), '3564959811529894228734180300843252711424')
     })
 
     it('should update odd element', () => {
       const tree = new MerkleTree(10, [1, 2, 3, 4, 5])
       tree.update(1, 42)
-      should().equal(tree.root(), '6642888742811380760154112624880866754768235565211186414088321870395007150538')
+      should().equal(tree.root(), '4576704573778433422699674477203122290688')
     })
 
     it('should update even element', () => {
       const tree = new MerkleTree(10, [1, 2, 3, 4, 5])
       tree.update(2, 42)
-      should().equal(tree.root(), '11739358667442647096377238675718917508981868161724701476635082606510350785683')
+      should().equal(tree.root(), '1807994110952186123819489133812038762496')
     })
 
     it('should update extra element', () => {
       const tree = new MerkleTree(10, [1, 2, 3, 4])
       tree.update(4, 5)
-      should().equal(tree.root(), '6341751103515285836339987888606244815365572869367801108789753151704260302930')
+      should().equal(tree.root(), '1099080610107164849381389194938128793600')
     })
 
     it('should fail to update incorrect index', () => {
@@ -177,15 +177,16 @@ describe('MerkleTree', () => {
       assert.deepEqual(path.pathIndices, [0, 1, 0, 0, 0, 0, 0, 0, 0, 0])
       assert.deepEqual(path.pathElements, [
         4,
-        '19814528709687996974327303300007262407299502847885145507292406548098437687919',
-        '21305827034995891902714687670641862055126514524916463201449278400604999416145',
-        '14506027710748750947258687001455876266559341618222612722926156490737302846427',
-        '4766583705360062980279572762279781527342845808161105063909171241304075622345',
-        '16640205414190175414380077665118269450294358858897019640557533278896634808665',
-        '13024477302430254842915163302704885770955784224100349847438808884122720088412',
-        '11345696205391376769769683860277269518617256738724086786512014734609753488820',
-        '17235543131546745471991808272245772046758360534180976603221801364506032471936',
-        '155962837046691114236524362966874066300454611955781275944230309195800494087',
+        '4027992409016347597424110157229339967488',
+        '3591172241203040147397382471352592629760',
+        '938972308169430750202858820582946897920',
+        '3743880566844110745576746962917825445888',
+        '2074434463882483178614385966084599578624',
+        '2808856778596740691845240322870189490176',
+        '4986731814143931240516913804278285467648',
+        '1918547053077726613961101558405545328640',
+        '5444383861051812288142814494928935059456',
+
       ])
     })
 
@@ -195,15 +196,16 @@ describe('MerkleTree', () => {
       assert.deepEqual(path.pathIndices, [1, 1, 0, 0, 0, 0, 0, 0, 0, 0])
       assert.deepEqual(path.pathElements, [
         3,
-        '19814528709687996974327303300007262407299502847885145507292406548098437687919',
-        '21305827034995891902714687670641862055126514524916463201449278400604999416145',
-        '14506027710748750947258687001455876266559341618222612722926156490737302846427',
-        '4766583705360062980279572762279781527342845808161105063909171241304075622345',
-        '16640205414190175414380077665118269450294358858897019640557533278896634808665',
-        '13024477302430254842915163302704885770955784224100349847438808884122720088412',
-        '11345696205391376769769683860277269518617256738724086786512014734609753488820',
-        '17235543131546745471991808272245772046758360534180976603221801364506032471936',
-        '155962837046691114236524362966874066300454611955781275944230309195800494087',
+        '4027992409016347597424110157229339967488',
+        '3591172241203040147397382471352592629760',
+        '938972308169430750202858820582946897920',
+        '3743880566844110745576746962917825445888',
+        '2074434463882483178614385966084599578624',
+        '2808856778596740691845240322870189490176',
+        '4986731814143931240516913804278285467648',
+        '1918547053077726613961101558405545328640',
+        '5444383861051812288142814494928935059456',
+
       ])
     })
 
@@ -220,15 +222,16 @@ describe('MerkleTree', () => {
       assert.deepEqual(path.pathIndices, [0, 1, 0, 0, 0, 0, 0, 0, 0, 0])
       assert.deepEqual(path.pathElements, [
         4,
-        '19814528709687996974327303300007262407299502847885145507292406548098437687919',
-        '21305827034995891902714687670641862055126514524916463201449278400604999416145',
-        '14506027710748750947258687001455876266559341618222612722926156490737302846427',
-        '4766583705360062980279572762279781527342845808161105063909171241304075622345',
-        '16640205414190175414380077665118269450294358858897019640557533278896634808665',
-        '13024477302430254842915163302704885770955784224100349847438808884122720088412',
-        '11345696205391376769769683860277269518617256738724086786512014734609753488820',
-        '17235543131546745471991808272245772046758360534180976603221801364506032471936',
-        '155962837046691114236524362966874066300454611955781275944230309195800494087',
+        '4027992409016347597424110157229339967488',
+        '3591172241203040147397382471352592629760',
+        '938972308169430750202858820582946897920',
+        '3743880566844110745576746962917825445888',
+        '2074434463882483178614385966084599578624',
+        '2808856778596740691845240322870189490176',
+        '4986731814143931240516913804278285467648',
+        '1918547053077726613961101558405545328640',
+        '5444383861051812288142814494928935059456',
+
       ])
     })
   })
@@ -238,16 +241,18 @@ describe('MerkleTree', () => {
     const layers = [
       [1, 2, 3, 4, 5],
       [
-        '19814528709687996974327303300007262407299502847885145507292406548098437687919',
-        '9256022917525827637821171443533757190340579068025270193352322268529570863974',
-        '21652272025144185891702495507858700052653521882982711576347377471507927142323',
+        '4027992409016347597424110157229339967488',
+        '923221781152860005594997320673730232320',
+        '752191049236692618445397735417537626112',
+
       ],
       [
-        '6464294476958346139385024074008223400825166653076969388043746597957512245037',
-        '21305827034995891902714687670641862055126514524916463201449278400604999416145',
+        '81822854828781486047086122479545722339328',
+        '3591172241203040147397382471352592629760',
+
       ],
-      ['13482485030738390475684870940688026655293260583748749623167469686138055064771'],
-      ['5734482689596254215043546232260442114954448597263096309106433719494772338840'],
+      ['2729943778107054496417267081388406865920'],
+      ['4562739390655416913642128116127918718976'],
     ]
 
     it('should return same elements in array', () => {