arnaucube
arnaucube/miden-cryptoPublic Self-hosted repository
miden-crypto/src/merkle/mmr/tests.rs
src/merkle/mmr/tests.rsRaw
  1use alloc::vec::Vec;
  2
  3use super::{
  4    super::{InnerNodeInfo, Rpo256, RpoDigest},
  5    bit::TrueBitPositionIterator,
  6    full::high_bitmask,
  7    leaf_to_corresponding_tree, nodes_in_forest, Mmr, MmrPeaks, PartialMmr,
  8};
  9use crate::{
 10    merkle::{int_to_node, InOrderIndex, MerklePath, MerkleTree, MmrProof, NodeIndex},
 11    Felt, Word,
 12};
 13
 14#[test]
 15fn test_position_equal_or_higher_than_leafs_is_never_contained() {
 16    let empty_forest = 0;
 17    for pos in 1..1024 {
 18        // pos is index, 0 based
 19        // tree is a length counter, 1 based
 20        // so a valid pos is always smaller, not equal, to tree
 21        assert_eq!(leaf_to_corresponding_tree(pos, pos), None);
 22        assert_eq!(leaf_to_corresponding_tree(pos, pos - 1), None);
 23        // and empty forest has no trees, so no position is valid
 24        assert_eq!(leaf_to_corresponding_tree(pos, empty_forest), None);
 25    }
 26}
 27
 28#[test]
 29fn test_position_zero_is_always_contained_by_the_highest_tree() {
 30    for leaves in 1..1024usize {
 31        let tree = leaves.ilog2();
 32        assert_eq!(leaf_to_corresponding_tree(0, leaves), Some(tree));
 33    }
 34}
 35
 36#[test]
 37fn test_leaf_to_corresponding_tree() {
 38    assert_eq!(leaf_to_corresponding_tree(0, 0b0001), Some(0));
 39    assert_eq!(leaf_to_corresponding_tree(0, 0b0010), Some(1));
 40    assert_eq!(leaf_to_corresponding_tree(0, 0b0011), Some(1));
 41    assert_eq!(leaf_to_corresponding_tree(0, 0b1011), Some(3));
 42
 43    // position one is always owned by the left-most tree
 44    assert_eq!(leaf_to_corresponding_tree(1, 0b0010), Some(1));
 45    assert_eq!(leaf_to_corresponding_tree(1, 0b0011), Some(1));
 46    assert_eq!(leaf_to_corresponding_tree(1, 0b1011), Some(3));
 47
 48    // position two starts as its own root, and then it is merged with the left-most tree
 49    assert_eq!(leaf_to_corresponding_tree(2, 0b0011), Some(0));
 50    assert_eq!(leaf_to_corresponding_tree(2, 0b0100), Some(2));
 51    assert_eq!(leaf_to_corresponding_tree(2, 0b1011), Some(3));
 52
 53    // position tree is merged on the left-most tree
 54    assert_eq!(leaf_to_corresponding_tree(3, 0b0011), None);
 55    assert_eq!(leaf_to_corresponding_tree(3, 0b0100), Some(2));
 56    assert_eq!(leaf_to_corresponding_tree(3, 0b1011), Some(3));
 57
 58    assert_eq!(leaf_to_corresponding_tree(4, 0b0101), Some(0));
 59    assert_eq!(leaf_to_corresponding_tree(4, 0b0110), Some(1));
 60    assert_eq!(leaf_to_corresponding_tree(4, 0b0111), Some(1));
 61    assert_eq!(leaf_to_corresponding_tree(4, 0b1000), Some(3));
 62
 63    assert_eq!(leaf_to_corresponding_tree(12, 0b01101), Some(0));
 64    assert_eq!(leaf_to_corresponding_tree(12, 0b01110), Some(1));
 65    assert_eq!(leaf_to_corresponding_tree(12, 0b01111), Some(1));
 66    assert_eq!(leaf_to_corresponding_tree(12, 0b10000), Some(4));
 67}
 68
 69#[test]
 70fn test_high_bitmask() {
 71    assert_eq!(high_bitmask(0), usize::MAX);
 72    assert_eq!(high_bitmask(1), usize::MAX << 1);
 73    assert_eq!(high_bitmask(usize::BITS - 2), 0b11usize.rotate_right(2));
 74    assert_eq!(high_bitmask(usize::BITS - 1), 0b1usize.rotate_right(1));
 75    assert_eq!(high_bitmask(usize::BITS), 0, "overflow should be handled");
 76}
 77
 78#[test]
 79fn test_nodes_in_forest() {
 80    assert_eq!(nodes_in_forest(0b0000), 0);
 81    assert_eq!(nodes_in_forest(0b0001), 1);
 82    assert_eq!(nodes_in_forest(0b0010), 3);
 83    assert_eq!(nodes_in_forest(0b0011), 4);
 84    assert_eq!(nodes_in_forest(0b0100), 7);
 85    assert_eq!(nodes_in_forest(0b0101), 8);
 86    assert_eq!(nodes_in_forest(0b0110), 10);
 87    assert_eq!(nodes_in_forest(0b0111), 11);
 88    assert_eq!(nodes_in_forest(0b1000), 15);
 89    assert_eq!(nodes_in_forest(0b1001), 16);
 90    assert_eq!(nodes_in_forest(0b1010), 18);
 91    assert_eq!(nodes_in_forest(0b1011), 19);
 92}
 93
 94#[test]
 95fn test_nodes_in_forest_single_bit() {
 96    assert_eq!(nodes_in_forest(2usize.pow(0)), 2usize.pow(1) - 1);
 97    assert_eq!(nodes_in_forest(2usize.pow(1)), 2usize.pow(2) - 1);
 98    assert_eq!(nodes_in_forest(2usize.pow(2)), 2usize.pow(3) - 1);
 99    assert_eq!(nodes_in_forest(2usize.pow(3)), 2usize.pow(4) - 1);
100
101    for bit in 0..(usize::BITS - 1) {
102        let size = 2usize.pow(bit + 1) - 1;
103        assert_eq!(nodes_in_forest(1usize << bit), size);
104    }
105}
106
107const LEAVES: [RpoDigest; 7] = [
108    int_to_node(0),
109    int_to_node(1),
110    int_to_node(2),
111    int_to_node(3),
112    int_to_node(4),
113    int_to_node(5),
114    int_to_node(6),
115];
116
117#[test]
118fn test_mmr_simple() {
119    let mut postorder = vec![
120        LEAVES[0],
121        LEAVES[1],
122        merge(LEAVES[0], LEAVES[1]),
123        LEAVES[2],
124        LEAVES[3],
125        merge(LEAVES[2], LEAVES[3]),
126    ];
127    postorder.push(merge(postorder[2], postorder[5]));
128    postorder.push(LEAVES[4]);
129    postorder.push(LEAVES[5]);
130    postorder.push(merge(LEAVES[4], LEAVES[5]));
131    postorder.push(LEAVES[6]);
132
133    let mut mmr = Mmr::new();
134    assert_eq!(mmr.forest(), 0);
135    assert_eq!(mmr.nodes.len(), 0);
136
137    mmr.add(LEAVES[0]);
138    assert_eq!(mmr.forest(), 1);
139    assert_eq!(mmr.nodes.len(), 1);
140    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
141
142    let acc = mmr.peaks();
143    assert_eq!(acc.num_leaves(), 1);
144    assert_eq!(acc.peaks(), &[postorder[0]]);
145
146    mmr.add(LEAVES[1]);
147    assert_eq!(mmr.forest(), 2);
148    assert_eq!(mmr.nodes.len(), 3);
149    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
150
151    let acc = mmr.peaks();
152    assert_eq!(acc.num_leaves(), 2);
153    assert_eq!(acc.peaks(), &[postorder[2]]);
154
155    mmr.add(LEAVES[2]);
156    assert_eq!(mmr.forest(), 3);
157    assert_eq!(mmr.nodes.len(), 4);
158    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
159
160    let acc = mmr.peaks();
161    assert_eq!(acc.num_leaves(), 3);
162    assert_eq!(acc.peaks(), &[postorder[2], postorder[3]]);
163
164    mmr.add(LEAVES[3]);
165    assert_eq!(mmr.forest(), 4);
166    assert_eq!(mmr.nodes.len(), 7);
167    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
168
169    let acc = mmr.peaks();
170    assert_eq!(acc.num_leaves(), 4);
171    assert_eq!(acc.peaks(), &[postorder[6]]);
172
173    mmr.add(LEAVES[4]);
174    assert_eq!(mmr.forest(), 5);
175    assert_eq!(mmr.nodes.len(), 8);
176    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
177
178    let acc = mmr.peaks();
179    assert_eq!(acc.num_leaves(), 5);
180    assert_eq!(acc.peaks(), &[postorder[6], postorder[7]]);
181
182    mmr.add(LEAVES[5]);
183    assert_eq!(mmr.forest(), 6);
184    assert_eq!(mmr.nodes.len(), 10);
185    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
186
187    let acc = mmr.peaks();
188    assert_eq!(acc.num_leaves(), 6);
189    assert_eq!(acc.peaks(), &[postorder[6], postorder[9]]);
190
191    mmr.add(LEAVES[6]);
192    assert_eq!(mmr.forest(), 7);
193    assert_eq!(mmr.nodes.len(), 11);
194    assert_eq!(mmr.nodes.as_slice(), &postorder[0..mmr.nodes.len()]);
195
196    let acc = mmr.peaks();
197    assert_eq!(acc.num_leaves(), 7);
198    assert_eq!(acc.peaks(), &[postorder[6], postorder[9], postorder[10]]);
199}
200
201#[test]
202fn test_mmr_open() {
203    let mmr: Mmr = LEAVES.into();
204    let h01 = merge(LEAVES[0], LEAVES[1]);
205    let h23 = merge(LEAVES[2], LEAVES[3]);
206
207    // node at pos 7 is the root
208    assert!(mmr.open(7).is_err(), "Element 7 is not in the tree, result should be None");
209
210    // node at pos 6 is the root
211    let empty: MerklePath = MerklePath::new(vec![]);
212    let opening = mmr
213        .open(6)
214        .expect("Element 6 is contained in the tree, expected an opening result.");
215    assert_eq!(opening.merkle_path, empty);
216    assert_eq!(opening.forest, mmr.forest);
217    assert_eq!(opening.position, 6);
218    assert!(
219        mmr.peaks().verify(LEAVES[6], opening),
220        "MmrProof should be valid for the current accumulator."
221    );
222
223    // nodes 4,5 are depth 1
224    let root_to_path = MerklePath::new(vec![LEAVES[4]]);
225    let opening = mmr
226        .open(5)
227        .expect("Element 5 is contained in the tree, expected an opening result.");
228    assert_eq!(opening.merkle_path, root_to_path);
229    assert_eq!(opening.forest, mmr.forest);
230    assert_eq!(opening.position, 5);
231    assert!(
232        mmr.peaks().verify(LEAVES[5], opening),
233        "MmrProof should be valid for the current accumulator."
234    );
235
236    let root_to_path = MerklePath::new(vec![LEAVES[5]]);
237    let opening = mmr
238        .open(4)
239        .expect("Element 4 is contained in the tree, expected an opening result.");
240    assert_eq!(opening.merkle_path, root_to_path);
241    assert_eq!(opening.forest, mmr.forest);
242    assert_eq!(opening.position, 4);
243    assert!(
244        mmr.peaks().verify(LEAVES[4], opening),
245        "MmrProof should be valid for the current accumulator."
246    );
247
248    // nodes 0,1,2,3 are detph 2
249    let root_to_path = MerklePath::new(vec![LEAVES[2], h01]);
250    let opening = mmr
251        .open(3)
252        .expect("Element 3 is contained in the tree, expected an opening result.");
253    assert_eq!(opening.merkle_path, root_to_path);
254    assert_eq!(opening.forest, mmr.forest);
255    assert_eq!(opening.position, 3);
256    assert!(
257        mmr.peaks().verify(LEAVES[3], opening),
258        "MmrProof should be valid for the current accumulator."
259    );
260
261    let root_to_path = MerklePath::new(vec![LEAVES[3], h01]);
262    let opening = mmr
263        .open(2)
264        .expect("Element 2 is contained in the tree, expected an opening result.");
265    assert_eq!(opening.merkle_path, root_to_path);
266    assert_eq!(opening.forest, mmr.forest);
267    assert_eq!(opening.position, 2);
268    assert!(
269        mmr.peaks().verify(LEAVES[2], opening),
270        "MmrProof should be valid for the current accumulator."
271    );
272
273    let root_to_path = MerklePath::new(vec![LEAVES[0], h23]);
274    let opening = mmr
275        .open(1)
276        .expect("Element 1 is contained in the tree, expected an opening result.");
277    assert_eq!(opening.merkle_path, root_to_path);
278    assert_eq!(opening.forest, mmr.forest);
279    assert_eq!(opening.position, 1);
280    assert!(
281        mmr.peaks().verify(LEAVES[1], opening),
282        "MmrProof should be valid for the current accumulator."
283    );
284
285    let root_to_path = MerklePath::new(vec![LEAVES[1], h23]);
286    let opening = mmr
287        .open(0)
288        .expect("Element 0 is contained in the tree, expected an opening result.");
289    assert_eq!(opening.merkle_path, root_to_path);
290    assert_eq!(opening.forest, mmr.forest);
291    assert_eq!(opening.position, 0);
292    assert!(
293        mmr.peaks().verify(LEAVES[0], opening),
294        "MmrProof should be valid for the current accumulator."
295    );
296}
297
298#[test]
299fn test_mmr_open_older_version() {
300    let mmr: Mmr = LEAVES.into();
301
302    fn is_even(v: &usize) -> bool {
303        v & 1 == 0
304    }
305
306    // merkle path of a node is empty if there are no elements to pair with it
307    for pos in (0..mmr.forest()).filter(is_even) {
308        let forest = pos + 1;
309        let proof = mmr.open_at(pos, forest).unwrap();
310        assert_eq!(proof.forest, forest);
311        assert_eq!(proof.merkle_path.nodes(), []);
312        assert_eq!(proof.position, pos);
313    }
314
315    // openings match that of a merkle tree
316    let mtree: MerkleTree = LEAVES[..4].try_into().unwrap();
317    for forest in 4..=LEAVES.len() {
318        for pos in 0..4 {
319            let idx = NodeIndex::new(2, pos).unwrap();
320            let path = mtree.get_path(idx).unwrap();
321            let proof = mmr.open_at(pos as usize, forest).unwrap();
322            assert_eq!(path, proof.merkle_path);
323        }
324    }
325    let mtree: MerkleTree = LEAVES[4..6].try_into().unwrap();
326    for forest in 6..=LEAVES.len() {
327        for pos in 0..2 {
328            let idx = NodeIndex::new(1, pos).unwrap();
329            let path = mtree.get_path(idx).unwrap();
330            // account for the bigger tree with 4 elements
331            let mmr_pos = (pos + 4) as usize;
332            let proof = mmr.open_at(mmr_pos, forest).unwrap();
333            assert_eq!(path, proof.merkle_path);
334        }
335    }
336}
337
338/// Tests the openings of a simple Mmr with a single tree of depth 8.
339#[test]
340fn test_mmr_open_eight() {
341    let leaves = [
342        int_to_node(0),
343        int_to_node(1),
344        int_to_node(2),
345        int_to_node(3),
346        int_to_node(4),
347        int_to_node(5),
348        int_to_node(6),
349        int_to_node(7),
350    ];
351
352    let mtree: MerkleTree = leaves.as_slice().try_into().unwrap();
353    let forest = leaves.len();
354    let mmr: Mmr = leaves.into();
355    let root = mtree.root();
356
357    let position = 0;
358    let proof = mmr.open(position).unwrap();
359    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
360    assert_eq!(proof, MmrProof { forest, position, merkle_path });
361    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
362
363    let position = 1;
364    let proof = mmr.open(position).unwrap();
365    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
366    assert_eq!(proof, MmrProof { forest, position, merkle_path });
367    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
368
369    let position = 2;
370    let proof = mmr.open(position).unwrap();
371    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
372    assert_eq!(proof, MmrProof { forest, position, merkle_path });
373    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
374
375    let position = 3;
376    let proof = mmr.open(position).unwrap();
377    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
378    assert_eq!(proof, MmrProof { forest, position, merkle_path });
379    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
380
381    let position = 4;
382    let proof = mmr.open(position).unwrap();
383    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
384    assert_eq!(proof, MmrProof { forest, position, merkle_path });
385    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
386
387    let position = 5;
388    let proof = mmr.open(position).unwrap();
389    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
390    assert_eq!(proof, MmrProof { forest, position, merkle_path });
391    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
392
393    let position = 6;
394    let proof = mmr.open(position).unwrap();
395    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
396    assert_eq!(proof, MmrProof { forest, position, merkle_path });
397    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
398
399    let position = 7;
400    let proof = mmr.open(position).unwrap();
401    let merkle_path = mtree.get_path(NodeIndex::new(3, position as u64).unwrap()).unwrap();
402    assert_eq!(proof, MmrProof { forest, position, merkle_path });
403    assert_eq!(proof.merkle_path.compute_root(position as u64, leaves[position]).unwrap(), root);
404}
405
406/// Tests the openings of Mmr with a 3 trees of depths 4, 2, and 1.
407#[test]
408fn test_mmr_open_seven() {
409    let mtree1: MerkleTree = LEAVES[..4].try_into().unwrap();
410    let mtree2: MerkleTree = LEAVES[4..6].try_into().unwrap();
411
412    let forest = LEAVES.len();
413    let mmr: Mmr = LEAVES.into();
414
415    let position = 0;
416    let proof = mmr.open(position).unwrap();
417    let merkle_path: MerklePath =
418        mtree1.get_path(NodeIndex::new(2, position as u64).unwrap()).unwrap();
419    assert_eq!(proof, MmrProof { forest, position, merkle_path });
420    assert_eq!(proof.merkle_path.compute_root(0, LEAVES[0]).unwrap(), mtree1.root());
421
422    let position = 1;
423    let proof = mmr.open(position).unwrap();
424    let merkle_path: MerklePath =
425        mtree1.get_path(NodeIndex::new(2, position as u64).unwrap()).unwrap();
426    assert_eq!(proof, MmrProof { forest, position, merkle_path });
427    assert_eq!(proof.merkle_path.compute_root(1, LEAVES[1]).unwrap(), mtree1.root());
428
429    let position = 2;
430    let proof = mmr.open(position).unwrap();
431    let merkle_path: MerklePath =
432        mtree1.get_path(NodeIndex::new(2, position as u64).unwrap()).unwrap();
433    assert_eq!(proof, MmrProof { forest, position, merkle_path });
434    assert_eq!(proof.merkle_path.compute_root(2, LEAVES[2]).unwrap(), mtree1.root());
435
436    let position = 3;
437    let proof = mmr.open(position).unwrap();
438    let merkle_path: MerklePath =
439        mtree1.get_path(NodeIndex::new(2, position as u64).unwrap()).unwrap();
440    assert_eq!(proof, MmrProof { forest, position, merkle_path });
441    assert_eq!(proof.merkle_path.compute_root(3, LEAVES[3]).unwrap(), mtree1.root());
442
443    let position = 4;
444    let proof = mmr.open(position).unwrap();
445    let merkle_path: MerklePath = mtree2.get_path(NodeIndex::new(1, 0u64).unwrap()).unwrap();
446    assert_eq!(proof, MmrProof { forest, position, merkle_path });
447    assert_eq!(proof.merkle_path.compute_root(0, LEAVES[4]).unwrap(), mtree2.root());
448
449    let position = 5;
450    let proof = mmr.open(position).unwrap();
451    let merkle_path: MerklePath = mtree2.get_path(NodeIndex::new(1, 1u64).unwrap()).unwrap();
452    assert_eq!(proof, MmrProof { forest, position, merkle_path });
453    assert_eq!(proof.merkle_path.compute_root(1, LEAVES[5]).unwrap(), mtree2.root());
454
455    let position = 6;
456    let proof = mmr.open(position).unwrap();
457    let merkle_path: MerklePath = [].as_ref().into();
458    assert_eq!(proof, MmrProof { forest, position, merkle_path });
459    assert_eq!(proof.merkle_path.compute_root(0, LEAVES[6]).unwrap(), LEAVES[6]);
460}
461
462#[test]
463fn test_mmr_get() {
464    let mmr: Mmr = LEAVES.into();
465    assert_eq!(mmr.get(0).unwrap(), LEAVES[0], "value at pos 0 must correspond");
466    assert_eq!(mmr.get(1).unwrap(), LEAVES[1], "value at pos 1 must correspond");
467    assert_eq!(mmr.get(2).unwrap(), LEAVES[2], "value at pos 2 must correspond");
468    assert_eq!(mmr.get(3).unwrap(), LEAVES[3], "value at pos 3 must correspond");
469    assert_eq!(mmr.get(4).unwrap(), LEAVES[4], "value at pos 4 must correspond");
470    assert_eq!(mmr.get(5).unwrap(), LEAVES[5], "value at pos 5 must correspond");
471    assert_eq!(mmr.get(6).unwrap(), LEAVES[6], "value at pos 6 must correspond");
472    assert!(mmr.get(7).is_err());
473}
474
475#[test]
476fn test_mmr_invariants() {
477    let mut mmr = Mmr::new();
478    for v in 1..=1028 {
479        mmr.add(int_to_node(v));
480        let accumulator = mmr.peaks();
481        assert_eq!(v as usize, mmr.forest(), "MMR leaf count must increase by one on every add");
482        assert_eq!(
483            v as usize,
484            accumulator.num_leaves(),
485            "MMR and its accumulator must match leaves count"
486        );
487        assert_eq!(
488            accumulator.num_leaves().count_ones() as usize,
489            accumulator.peaks().len(),
490            "bits on leaves must match the number of peaks"
491        );
492
493        let expected_nodes: usize = TrueBitPositionIterator::new(mmr.forest())
494            .map(|bit_pos| nodes_in_forest(1 << bit_pos))
495            .sum();
496
497        assert_eq!(
498            expected_nodes,
499            mmr.nodes.len(),
500            "the sum of every tree size must be equal to the number of nodes in the MMR (forest: {:b})",
501            mmr.forest(),
502        );
503    }
504}
505
506#[test]
507fn test_bit_position_iterator() {
508    assert_eq!(TrueBitPositionIterator::new(0).count(), 0);
509    assert_eq!(TrueBitPositionIterator::new(0).rev().count(), 0);
510
511    assert_eq!(TrueBitPositionIterator::new(1).collect::<Vec<u32>>(), vec![0]);
512    assert_eq!(TrueBitPositionIterator::new(1).rev().collect::<Vec<u32>>(), vec![0],);
513
514    assert_eq!(TrueBitPositionIterator::new(2).collect::<Vec<u32>>(), vec![1]);
515    assert_eq!(TrueBitPositionIterator::new(2).rev().collect::<Vec<u32>>(), vec![1],);
516
517    assert_eq!(TrueBitPositionIterator::new(3).collect::<Vec<u32>>(), vec![0, 1],);
518    assert_eq!(TrueBitPositionIterator::new(3).rev().collect::<Vec<u32>>(), vec![1, 0],);
519
520    assert_eq!(
521        TrueBitPositionIterator::new(0b11010101).collect::<Vec<u32>>(),
522        vec![0, 2, 4, 6, 7],
523    );
524    assert_eq!(
525        TrueBitPositionIterator::new(0b11010101).rev().collect::<Vec<u32>>(),
526        vec![7, 6, 4, 2, 0],
527    );
528}
529
530#[test]
531fn test_mmr_inner_nodes() {
532    let mmr: Mmr = LEAVES.into();
533    let nodes: Vec<InnerNodeInfo> = mmr.inner_nodes().collect();
534
535    let h01 = Rpo256::merge(&[LEAVES[0], LEAVES[1]]);
536    let h23 = Rpo256::merge(&[LEAVES[2], LEAVES[3]]);
537    let h0123 = Rpo256::merge(&[h01, h23]);
538    let h45 = Rpo256::merge(&[LEAVES[4], LEAVES[5]]);
539    let postorder = vec![
540        InnerNodeInfo {
541            value: h01,
542            left: LEAVES[0],
543            right: LEAVES[1],
544        },
545        InnerNodeInfo {
546            value: h23,
547            left: LEAVES[2],
548            right: LEAVES[3],
549        },
550        InnerNodeInfo { value: h0123, left: h01, right: h23 },
551        InnerNodeInfo {
552            value: h45,
553            left: LEAVES[4],
554            right: LEAVES[5],
555        },
556    ];
557
558    assert_eq!(postorder, nodes);
559}
560
561#[test]
562fn test_mmr_peaks() {
563    let mmr: Mmr = LEAVES.into();
564
565    let forest = 0b0001;
566    let acc = mmr.peaks_at(forest).unwrap();
567    assert_eq!(acc.num_leaves(), forest);
568    assert_eq!(acc.peaks(), &[mmr.nodes[0]]);
569
570    let forest = 0b0010;
571    let acc = mmr.peaks_at(forest).unwrap();
572    assert_eq!(acc.num_leaves(), forest);
573    assert_eq!(acc.peaks(), &[mmr.nodes[2]]);
574
575    let forest = 0b0011;
576    let acc = mmr.peaks_at(forest).unwrap();
577    assert_eq!(acc.num_leaves(), forest);
578    assert_eq!(acc.peaks(), &[mmr.nodes[2], mmr.nodes[3]]);
579
580    let forest = 0b0100;
581    let acc = mmr.peaks_at(forest).unwrap();
582    assert_eq!(acc.num_leaves(), forest);
583    assert_eq!(acc.peaks(), &[mmr.nodes[6]]);
584
585    let forest = 0b0101;
586    let acc = mmr.peaks_at(forest).unwrap();
587    assert_eq!(acc.num_leaves(), forest);
588    assert_eq!(acc.peaks(), &[mmr.nodes[6], mmr.nodes[7]]);
589
590    let forest = 0b0110;
591    let acc = mmr.peaks_at(forest).unwrap();
592    assert_eq!(acc.num_leaves(), forest);
593    assert_eq!(acc.peaks(), &[mmr.nodes[6], mmr.nodes[9]]);
594
595    let forest = 0b0111;
596    let acc = mmr.peaks_at(forest).unwrap();
597    assert_eq!(acc.num_leaves(), forest);
598    assert_eq!(acc.peaks(), &[mmr.nodes[6], mmr.nodes[9], mmr.nodes[10]]);
599}
600
601#[test]
602fn test_mmr_hash_peaks() {
603    let mmr: Mmr = LEAVES.into();
604    let peaks = mmr.peaks();
605
606    let first_peak = Rpo256::merge(&[
607        Rpo256::merge(&[LEAVES[0], LEAVES[1]]),
608        Rpo256::merge(&[LEAVES[2], LEAVES[3]]),
609    ]);
610    let second_peak = Rpo256::merge(&[LEAVES[4], LEAVES[5]]);
611    let third_peak = LEAVES[6];
612
613    // minimum length is 16
614    let mut expected_peaks = [first_peak, second_peak, third_peak].to_vec();
615    expected_peaks.resize(16, RpoDigest::default());
616    assert_eq!(peaks.hash_peaks(), Rpo256::hash_elements(&digests_to_elements(&expected_peaks)));
617}
618
619#[test]
620fn test_mmr_peaks_hash_less_than_16() {
621    let mut peaks = Vec::new();
622
623    for i in 0..16 {
624        peaks.push(int_to_node(i));
625
626        let num_leaves = (1 << peaks.len()) - 1;
627        let accumulator = MmrPeaks::new(num_leaves, peaks.clone()).unwrap();
628
629        // minimum length is 16
630        let mut expected_peaks = peaks.clone();
631        expected_peaks.resize(16, RpoDigest::default());
632        assert_eq!(
633            accumulator.hash_peaks(),
634            Rpo256::hash_elements(&digests_to_elements(&expected_peaks))
635        );
636    }
637}
638
639#[test]
640fn test_mmr_peaks_hash_odd() {
641    let peaks: Vec<_> = (0..=17).map(int_to_node).collect();
642
643    let num_leaves = (1 << peaks.len()) - 1;
644    let accumulator = MmrPeaks::new(num_leaves, peaks.clone()).unwrap();
645
646    // odd length bigger than 16 is padded to the next even number
647    let mut expected_peaks = peaks;
648    expected_peaks.resize(18, RpoDigest::default());
649    assert_eq!(
650        accumulator.hash_peaks(),
651        Rpo256::hash_elements(&digests_to_elements(&expected_peaks))
652    );
653}
654
655#[test]
656fn test_mmr_delta() {
657    let mmr: Mmr = LEAVES.into();
658    let acc = mmr.peaks();
659
660    // original_forest can't have more elements
661    assert!(
662        mmr.get_delta(LEAVES.len() + 1, mmr.forest()).is_err(),
663        "Can not provide updates for a newer Mmr"
664    );
665
666    // if the number of elements is the same there is no change
667    assert!(
668        mmr.get_delta(LEAVES.len(), mmr.forest()).unwrap().data.is_empty(),
669        "There are no updates for the same Mmr version"
670    );
671
672    // missing the last element added, which is itself a tree peak
673    assert_eq!(mmr.get_delta(6, mmr.forest()).unwrap().data, vec![acc.peaks()[2]], "one peak");
674
675    // missing the sibling to complete the tree of depth 2, and the last element
676    assert_eq!(
677        mmr.get_delta(5, mmr.forest()).unwrap().data,
678        vec![LEAVES[5], acc.peaks()[2]],
679        "one sibling, one peak"
680    );
681
682    // missing the whole last two trees, only send the peaks
683    assert_eq!(
684        mmr.get_delta(4, mmr.forest()).unwrap().data,
685        vec![acc.peaks()[1], acc.peaks()[2]],
686        "two peaks"
687    );
688
689    // missing the sibling to complete the first tree, and the two last trees
690    assert_eq!(
691        mmr.get_delta(3, mmr.forest()).unwrap().data,
692        vec![LEAVES[3], acc.peaks()[1], acc.peaks()[2]],
693        "one sibling, two peaks"
694    );
695
696    // missing half of the first tree, only send the computed element (not the leaves), and the new
697    // peaks
698    assert_eq!(
699        mmr.get_delta(2, mmr.forest()).unwrap().data,
700        vec![mmr.nodes[5], acc.peaks()[1], acc.peaks()[2]],
701        "one sibling, two peaks"
702    );
703
704    assert_eq!(
705        mmr.get_delta(1, mmr.forest()).unwrap().data,
706        vec![LEAVES[1], mmr.nodes[5], acc.peaks()[1], acc.peaks()[2]],
707        "one sibling, two peaks"
708    );
709
710    assert_eq!(&mmr.get_delta(0, mmr.forest()).unwrap().data, acc.peaks(), "all peaks");
711}
712
713#[test]
714fn test_mmr_delta_old_forest() {
715    let mmr: Mmr = LEAVES.into();
716
717    // from_forest must be smaller-or-equal to to_forest
718    for version in 1..=mmr.forest() {
719        assert!(mmr.get_delta(version + 1, version).is_err());
720    }
721
722    // when from_forest and to_forest are equal, there are no updates
723    for version in 1..=mmr.forest() {
724        let delta = mmr.get_delta(version, version).unwrap();
725        assert!(delta.data.is_empty());
726        assert_eq!(delta.forest, version);
727    }
728
729    // test update which merges the odd peak to the right
730    for count in 0..(mmr.forest() / 2) {
731        // *2 because every iteration tests a pair
732        // +1 because the Mmr is 1-indexed
733        let from_forest = (count * 2) + 1;
734        let to_forest = (count * 2) + 2;
735        let delta = mmr.get_delta(from_forest, to_forest).unwrap();
736
737        // *2 because every iteration tests a pair
738        // +1 because sibling is the odd element
739        let sibling = (count * 2) + 1;
740        assert_eq!(delta.data, [LEAVES[sibling]]);
741        assert_eq!(delta.forest, to_forest);
742    }
743
744    let version = 4;
745    let delta = mmr.get_delta(1, version).unwrap();
746    assert_eq!(delta.data, [mmr.nodes[1], mmr.nodes[5]]);
747    assert_eq!(delta.forest, version);
748
749    let version = 5;
750    let delta = mmr.get_delta(1, version).unwrap();
751    assert_eq!(delta.data, [mmr.nodes[1], mmr.nodes[5], mmr.nodes[7]]);
752    assert_eq!(delta.forest, version);
753}
754
755#[test]
756fn test_partial_mmr_simple() {
757    let mmr: Mmr = LEAVES.into();
758    let peaks = mmr.peaks();
759    let mut partial: PartialMmr = peaks.clone().into();
760
761    // check initial state of the partial mmr
762    assert_eq!(partial.peaks(), peaks);
763    assert_eq!(partial.forest(), peaks.num_leaves());
764    assert_eq!(partial.forest(), LEAVES.len());
765    assert_eq!(partial.peaks().num_peaks(), 3);
766    assert_eq!(partial.nodes.len(), 0);
767
768    // check state after adding tracking one element
769    let proof1 = mmr.open(0).unwrap();
770    let el1 = mmr.get(proof1.position).unwrap();
771    partial.track(proof1.position, el1, &proof1.merkle_path).unwrap();
772
773    // check the number of nodes increased by the number of nodes in the proof
774    assert_eq!(partial.nodes.len(), proof1.merkle_path.len());
775    // check the values match
776    let idx = InOrderIndex::from_leaf_pos(proof1.position);
777    assert_eq!(partial.nodes[&idx.sibling()], proof1.merkle_path[0]);
778    let idx = idx.parent();
779    assert_eq!(partial.nodes[&idx.sibling()], proof1.merkle_path[1]);
780
781    let proof2 = mmr.open(1).unwrap();
782    let el2 = mmr.get(proof2.position).unwrap();
783    partial.track(proof2.position, el2, &proof2.merkle_path).unwrap();
784
785    // check the number of nodes increased by a single element (the one that is not shared)
786    assert_eq!(partial.nodes.len(), 3);
787    // check the values match
788    let idx = InOrderIndex::from_leaf_pos(proof2.position);
789    assert_eq!(partial.nodes[&idx.sibling()], proof2.merkle_path[0]);
790    let idx = idx.parent();
791    assert_eq!(partial.nodes[&idx.sibling()], proof2.merkle_path[1]);
792}
793
794#[test]
795fn test_partial_mmr_update_single() {
796    let mut full = Mmr::new();
797    let zero = int_to_node(0);
798    full.add(zero);
799    let mut partial: PartialMmr = full.peaks().into();
800
801    let proof = full.open(0).unwrap();
802    partial.track(proof.position, zero, &proof.merkle_path).unwrap();
803
804    for i in 1..100 {
805        let node = int_to_node(i);
806        full.add(node);
807        let delta = full.get_delta(partial.forest(), full.forest()).unwrap();
808        partial.apply(delta).unwrap();
809
810        assert_eq!(partial.forest(), full.forest());
811        assert_eq!(partial.peaks(), full.peaks());
812
813        let proof1 = full.open(i as usize).unwrap();
814        partial.track(proof1.position, node, &proof1.merkle_path).unwrap();
815        let proof2 = partial.open(proof1.position).unwrap().unwrap();
816        assert_eq!(proof1.merkle_path, proof2.merkle_path);
817    }
818}
819
820#[test]
821fn test_mmr_add_invalid_odd_leaf() {
822    let mmr: Mmr = LEAVES.into();
823    let acc = mmr.peaks();
824    let mut partial: PartialMmr = acc.clone().into();
825
826    let empty = MerklePath::new(Vec::new());
827
828    // None of the other leaves should work
829    for node in LEAVES.iter().cloned().rev().skip(1) {
830        let result = partial.track(LEAVES.len() - 1, node, &empty);
831        assert!(result.is_err());
832    }
833
834    let result = partial.track(LEAVES.len() - 1, LEAVES[6], &empty);
835    assert!(result.is_ok());
836}
837
838mod property_tests {
839    use proptest::prelude::*;
840
841    use super::leaf_to_corresponding_tree;
842
843    proptest! {
844        #[test]
845        fn test_last_position_is_always_contained_in_the_last_tree(leaves in any::<usize>().prop_filter("cant have an empty tree", |v| *v != 0)) {
846            let last_pos = leaves - 1;
847            let lowest_bit = leaves.trailing_zeros();
848
849            assert_eq!(
850                leaf_to_corresponding_tree(last_pos, leaves),
851                Some(lowest_bit),
852            );
853        }
854    }
855
856    proptest! {
857        #[test]
858        fn test_contained_tree_is_always_power_of_two((leaves, pos) in any::<usize>().prop_flat_map(|v| (Just(v), 0..v))) {
859            let tree_bit = leaf_to_corresponding_tree(pos, leaves).expect("pos is smaller than leaves, there should always be a corresponding tree");
860            let mask = 1usize << tree_bit;
861
862            assert!(tree_bit < usize::BITS, "the result must be a bit in usize");
863            assert!(mask & leaves != 0, "the result should be a tree in leaves");
864        }
865    }
866}
867
868// HELPER FUNCTIONS
869// ================================================================================================
870
871fn digests_to_elements(digests: &[RpoDigest]) -> Vec<Felt> {
872    digests.iter().flat_map(Word::from).collect()
873}
874
875// short hand for the rpo hash, used to make test code more concise and easy to read
876fn merge(l: RpoDigest, r: RpoDigest) -> RpoDigest {
877    Rpo256::merge(&[l, r])
878}