Merge pull request #1004 from privacy-scaling-explorations/test/circuits

test(circuits): refactor and add tests for the circom circuits

circuits/circom/tallyVotes.circom

@@ -7,9 +7,7 @@ include "./hasherSha256.circom";
 include "./hasherPoseidon.circom";
 include "./unpackElement.circom";
 
-/*
- * Tally votes in the ballots, batch by batch.
- */
+// Tally votes in the ballots, batch by batch.
 template TallyVotes(
     stateTreeDepth,
     intStateTreeDepth,
@@ -192,10 +190,8 @@ template TallyVotes(
     }
 }
 
-/*
- * Verifies the commitment to the current results. Also computes and outputs a
- * commitment to the new results.
- */
+// Verifies the commitment to the current results. Also computes and outputs a
+// commitment to the new results.
 template ResultCommitmentVerifier(voteOptionTreeDepth) {
     var TREE_ARITY = 5;
     var numVoteOptions = TREE_ARITY ** voteOptionTreeDepth;
@@ -257,7 +253,7 @@ template ResultCommitmentVerifier(voteOptionTreeDepth) {
     currentTallyCommitmentHasher.in[1] <== currentSpentVoiceCreditsCommitment.hash;
     currentTallyCommitmentHasher.in[2] <== currentPerVOSpentVoiceCreditsCommitment.hash;
 
-    /*currentTallyCommitmentHasher.hash === currentTallyCommitment;*/
+    // currentTallyCommitmentHasher.hash === currentTallyCommitment
     // Check if the current tally commitment is correct only if this is not the first batch
     component iz = IsZero();
     iz.in <== isFirstBatch;
@@ -305,9 +301,6 @@ template ResultCommitmentVerifier(voteOptionTreeDepth) {
     newTallyCommitmentHasher.in[1] <== newSpentVoiceCreditsCommitment.hash;
     newTallyCommitmentHasher.in[2] <== newPerVOSpentVoiceCreditsCommitment.hash;
 
-    /*log(newResultsCommitment.hash);*/
-    /*log(newSpentVoiceCreditsCommitment.hash);*/
-    /*log(newPerVOSpentVoiceCreditsCommitment.hash);*/
     newTallyCommitmentHasher.hash === newTallyCommitment;
 }
 

circuits/circom/trees/checkRoot.circom

@@ -1,40 +1,8 @@
 pragma circom 2.0.0;
 include "../hasherPoseidon.circom";
 
-/*template QuinCheckRootWithSha256(levels, subLevels) {*/
-    /*// Given a quin Merkle root and a list of leaves, check if the root is the*/
-    /*// correct result of inserting all the leaves into the tree in the given*/
-    /*// order. Uses SHA256 instead of Poseidon to hash levels up to subLevels*/
-
-    /*assert(levels > 0);*/
-    /*assert(subLevels <= levels);*/
-    /*var LEAVES_PER_NODE = 5;*/
-
-    /*// The total number of leaves*/
-    /*var totalLeaves = LEAVES_PER_NODE ** levels;*/
-
-    /*signal input leaves[totalLeaves];*/
-    /*signal output root;*/
-
-    /*// The total number of hashers*/
-    /*var numHashers = 0;*/
-    /*for (var i = 0; i < levels; i ++) {*/
-        /*numHashers += LEAVES_PER_NODE ** i;*/
-    /*}*/
-
-    /*// The number of SHA256 hashers*/
-    /*var numShaHashers = 0;*/
-    /*for (var i = 0; i < subLevels; i ++) {*/
-        /*numShaHashers += LEAVES_PER_NODE ** i;*/
-    /*}*/
-
-    /*var numPoseidonHashers = numHashers - numShaHashers;*/
-
-
-/*}*/
-
-// Given a quin Merkle root and a list of leaves, check if the root is the
-// correct result of inserting all the leaves into the tree in the given
+// Given a list of leaves, compute the root of the merkle tree
+// by inserting all the leaves into the tree in the given
 // order.
 template QuinCheckRoot(levels) {
     var LEAVES_PER_NODE = 5;

circuits/circom/trees/incrementalMerkleTree.circom

@@ -6,6 +6,7 @@ pragma circom 2.0.0;
 include "../../node_modules/circomlib/circuits/mux1.circom";
 include "../hasherPoseidon.circom";
 
+// recompute a merkle root from a leaf and a path
 template MerkleTreeInclusionProof(n_levels) {
     signal input leaf;
     signal input path_index[n_levels];
@@ -41,8 +42,8 @@ template MerkleTreeInclusionProof(n_levels) {
     root <== levelHashes[n_levels];
 }
 
+// Ensures that a leaf exists within a merkletree with given `root`
 template LeafExists(levels){
-  // Ensures that a leaf exists within a merkletree with given `root`
 
   // levels is depth of tree
   signal input leaf;
@@ -62,11 +63,10 @@ template LeafExists(levels){
   root === merkletree.root;
 }
 
+// Given a Merkle root and a list of leaves, check if the root is the
+// correct result of inserting all the leaves into the tree (in the given
+// order)
 template CheckRoot(levels) {
-    // Given a Merkle root and a list of leaves, check if the root is the
-    // correct result of inserting all the leaves into the tree (in the given
-    // order)
-
     // Circom has some perticularities which limit the code patterns we can
     // use.
 

circuits/circom/trees/incrementalQuinTree.circom

@@ -11,16 +11,16 @@ include "../utils.circom";
 // circuit to hash leaves, which supports up to 5 input elements.
 
 /*
-Note: circom has some particularities which limit the code patterns we can use.
-
-- You can only assign a value to a signal once.
-- A component's input signal must only be wired to another component's output
-  signal.
-- Variables can store linear combinations, and can also be used for loops,
-  declaring sizes of things, and anything that is not related to inputs of a
-  circuit.
-- The compiler fails whenever you try to mix invalid elements.
-- You can't use a signal as a list index.
+    Note: circom has some particularities which limit the code patterns we can use.
+
+    - You can only assign a value to a signal once.
+    - A component's input signal must only be wired to another component's output
+    signal.
+    - Variables can store linear combinations, and can also be used for loops,
+    declaring sizes of things, and anything that is not related to inputs of a
+    circuit.
+    - The compiler fails whenever you try to mix invalid elements.
+    - You can't use a signal as a list index.
 */
 
 // Given a list of items and an index, output the item at the position denoted
@@ -137,6 +137,8 @@ template Splicer(numItems) {
     }
 }
 
+// Given a list of leaves, as well as the path to the root,
+// compute the root
 template QuinTreeInclusionProof(levels) {
     // Each node has 5 leaves
     var LEAVES_PER_NODE = 5;
@@ -185,9 +187,8 @@ template QuinTreeInclusionProof(levels) {
     root <== hashers[levels - 1].hash;
 }
 
+// Ensures that a leaf exists within a quintree with given `root`
 template QuinLeafExists(levels){
-    // Ensures that a leaf exists within a quintree with given `root`
-
     var LEAVES_PER_NODE = 5;
     var LEAVES_PER_PATH_LEVEL = LEAVES_PER_NODE - 1;