| 1 | package readcoord |
| 2 | |
| 3 | import ( |
| 4 | "math/rand" |
| 5 | "slices" |
| 6 | "testing" |
| 7 | |
| 8 | "reasonix/internal/tool" |
| 9 | ) |
| 10 | |
| 11 | func ranges(pairs ...int) []tool.ReadRange { |
| 12 | out := make([]tool.ReadRange, 0, len(pairs)/2) |
| 13 | for i := 0; i+1 < len(pairs); i += 2 { |
| 14 | out = append(out, tool.ReadRange{Start: pairs[i], End: pairs[i+1]}) |
| 15 | } |
| 16 | return out |
| 17 | } |
| 18 | |
| 19 | func sameRanges(a, b []tool.ReadRange) bool { return slices.Equal(Normalize(a), Normalize(b)) } |
| 20 | |
| 21 | func TestNormalizeMergesOverlapsAndAdjacency(t *testing.T) { |
| 22 | cases := []struct { |
| 23 | name string |
| 24 | in []tool.ReadRange |
| 25 | want []tool.ReadRange |
| 26 | }{ |
| 27 | {"empty dropped", ranges(5, 5, 7, 3), nil}, |
| 28 | {"adjacent merge", ranges(0, 5, 5, 9), ranges(0, 9)}, |
| 29 | {"overlap merge", ranges(0, 6, 4, 9), ranges(0, 9)}, |
| 30 | {"disjoint kept", ranges(0, 2, 5, 7), ranges(0, 2, 5, 7)}, |
| 31 | {"contained dropped", ranges(0, 10, 3, 5), ranges(0, 10)}, |
| 32 | } |
| 33 | for _, tc := range cases { |
| 34 | t.Run(tc.name, func(t *testing.T) { |
| 35 | if got := Normalize(tc.in); !sameRanges(got, tc.want) { |
| 36 | t.Fatalf("Normalize(%+v) = %+v, want %+v", tc.in, got, tc.want) |
| 37 | } |
| 38 | }) |
| 39 | } |
| 40 | } |
| 41 | |
| 42 | func TestSubtractReturnsUncoveredParts(t *testing.T) { |
| 43 | cases := []struct { |
| 44 | name string |
| 45 | want []tool.ReadRange |
| 46 | have []tool.ReadRange |
| 47 | wantLeft []tool.ReadRange |
| 48 | wantCover bool |
| 49 | }{ |
| 50 | {"nothing covered", ranges(0, 10), nil, ranges(0, 10), false}, |
| 51 | {"prefix covered", ranges(0, 10), ranges(0, 4), ranges(4, 10), false}, |
| 52 | {"middle hole", ranges(0, 10), ranges(0, 4, 6, 10), ranges(4, 6), false}, |
| 53 | {"fully covered", ranges(2, 5), ranges(0, 10), nil, true}, |
| 54 | {"tail covered", ranges(0, 10), ranges(4, 10), ranges(0, 4), false}, |
| 55 | } |
| 56 | for _, tc := range cases { |
| 57 | t.Run(tc.name, func(t *testing.T) { |
| 58 | got := Subtract(tc.want, tc.have) |
| 59 | if !sameRanges(got, tc.wantLeft) { |
| 60 | t.Fatalf("Subtract(%+v, %+v) = %+v, want %+v", tc.want, tc.have, got, tc.wantLeft) |
| 61 | } |
| 62 | if Covers(tc.have, tc.want) != tc.wantCover { |
| 63 | t.Fatalf("Covers(%+v, %+v) = %v, want %v", tc.have, tc.want, !tc.wantCover, tc.wantCover) |
| 64 | } |
| 65 | }) |
| 66 | } |
| 67 | } |
| 68 | |
| 69 | func randomRanges(rng *rand.Rand, n int) []tool.ReadRange { |
| 70 | out := make([]tool.ReadRange, 0, n) |
| 71 | for range n { |
| 72 | start := rng.Intn(40) |
| 73 | out = append(out, tool.ReadRange{Start: start, End: start + rng.Intn(12)}) |
| 74 | } |
| 75 | return out |
| 76 | } |
| 77 | |
| 78 | // TestCoverageAlgebraHoldsOverRandomSplits checks the property every paging |
| 79 | // decision depends on: the uncovered parts of a requirement, added back to what |
| 80 | // was already covered, cover the requirement exactly, and share no line with it. |
| 81 | func TestCoverageAlgebraHoldsOverRandomSplits(t *testing.T) { |
| 82 | rng := rand.New(rand.NewSource(7)) |
| 83 | for i := range 2000 { |
| 84 | want := randomRanges(rng, 1+rng.Intn(5)) |
| 85 | have := randomRanges(rng, 1+rng.Intn(5)) |
| 86 | gaps := Subtract(want, have) |
| 87 | if !Covers(append(append([]tool.ReadRange(nil), have...), gaps...), want) { |
| 88 | t.Fatalf("case %d: covered %+v plus gaps %+v does not cover %+v", i, have, gaps, want) |
| 89 | } |
| 90 | for _, gap := range gaps { |
| 91 | for _, h := range Normalize(have) { |
| 92 | if start, end := max(gap.Start, h.Start), min(gap.End, h.End); start < end { |
| 93 | t.Fatalf("case %d: gap %+v overlaps covered %+v", i, gap, h) |
| 94 | } |
| 95 | } |
| 96 | } |
| 97 | } |
| 98 | } |
| 99 | |
| 100 | func TestNormalizeIsOrderIndependent(t *testing.T) { |
| 101 | rng := rand.New(rand.NewSource(11)) |
| 102 | for i := range 500 { |
| 103 | in := randomRanges(rng, 1+rng.Intn(6)) |
| 104 | want := Normalize(in) |
| 105 | shuffled := append([]tool.ReadRange(nil), in...) |
| 106 | rng.Shuffle(len(shuffled), func(a, b int) { shuffled[a], shuffled[b] = shuffled[b], shuffled[a] }) |
| 107 | if got := Normalize(shuffled); !sameRanges(got, want) { |
| 108 | t.Fatalf("case %d: Normalize depends on order: %+v vs %+v", i, got, want) |
| 109 | } |
| 110 | if again := Normalize(want); !sameRanges(again, want) { |
| 111 | t.Fatalf("case %d: Normalize is not idempotent: %+v vs %+v", i, again, want) |
| 112 | } |
| 113 | } |
| 114 | } |
| 115 | |
| 116 | func FuzzCoverageRecombination(f *testing.F) { |
| 117 | f.Add([]byte{0, 10, 3, 6}, []byte{0, 4, 8, 10}) |
| 118 | f.Fuzz(func(t *testing.T, wantRaw, haveRaw []byte) { |
| 119 | want := decodeRanges(wantRaw) |
| 120 | have := decodeRanges(haveRaw) |
| 121 | gaps := Subtract(want, have) |
| 122 | if !Covers(append(append([]tool.ReadRange(nil), have...), gaps...), want) { |
| 123 | t.Fatalf("covered %+v plus gaps %+v does not cover %+v", have, gaps, want) |
| 124 | } |
| 125 | }) |
| 126 | } |
| 127 | |
| 128 | func decodeRanges(raw []byte) []tool.ReadRange { |
| 129 | out := make([]tool.ReadRange, 0, len(raw)/2) |
| 130 | for i := 0; i+1 < len(raw); i += 2 { |
| 131 | start := int(raw[i]) |
| 132 | out = append(out, tool.ReadRange{Start: start, End: start + int(raw[i+1])}) |
| 133 | } |
| 134 | return out |
| 135 | } |
| 136 |