test: add fuzz test for coverage

Signed-off-by: Zxilly <[email protected]>
Zxilly · Jun 19, 2024 · 0f50890 · 0f50890
1 parent 1f0d4a5
commit 0f50890
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Showing 2 changed files with 122 additions and 50 deletions.
diff --git a/internal/entity/addr_test.go b/internal/entity/addr_test.go
@@ -3,9 +3,7 @@ package entity_test
 import (
 	"testing"
 
-	"github.com/samber/lo"
 	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
 
 	"github.com/Zxilly/go-size-analyzer/internal/entity"
 )
@@ -62,54 +60,6 @@ func TestAddrPosStringWithZeroAddr(t *testing.T) {
 	assert.Equal(t, expected, result)
 }
 
-func TestMergeCoverage(t *testing.T) {
-	cov1 := entity.AddrCoverage{
-		&entity.CoveragePart{
-			Pos:   &entity.AddrPos{Addr: 4096, Size: 256, Type: entity.AddrTypeData},
-			Addrs: []*entity.Addr{{}},
-		},
-	}
-	cov2 := entity.AddrCoverage{
-		&entity.CoveragePart{
-			Pos:   &entity.AddrPos{Addr: 4351, Size: 256, Type: entity.AddrTypeData},
-			Addrs: []*entity.Addr{{}},
-		},
-	}
-
-	expected := entity.AddrCoverage{
-		&entity.CoveragePart{
-			Pos:   &entity.AddrPos{Addr: 4096, Size: 511, Type: entity.AddrTypeData},
-			Addrs: nil,
-		},
-	}
-
-	result, err := entity.MergeAndCleanCoverage([]entity.AddrCoverage{cov1, cov2})
-	require.NoError(t, err)
-
-	// reset result Addrs
-	lo.ForEach(result, func(part *entity.CoveragePart, _ int) {
-		part.Addrs = nil
-	})
-
-	assert.Equal(t, expected, result)
-
-	cov3 := entity.AddrCoverage{
-		&entity.CoveragePart{
-			Pos:   &entity.AddrPos{Addr: 4096, Size: 256, Type: entity.AddrTypeText},
-			Addrs: []*entity.Addr{{}},
-		},
-	}
-	cov4 := entity.AddrCoverage{
-		&entity.CoveragePart{
-			Pos:   &entity.AddrPos{Addr: 4160, Size: 128, Type: entity.AddrTypeData}, // 与 cov3 有重叠
-			Addrs: []*entity.Addr{{}},
-		},
-	}
-
-	_, err = entity.MergeAndCleanCoverage([]entity.AddrCoverage{cov3, cov4})
-	assert.Error(t, err)
-}
-
 func TestCoveragePartStringWithMultipleAddrs(t *testing.T) {
 	addrPos := &entity.AddrPos{
 		Addr: 4096,

diff --git a/internal/entity/coverage_test.go b/internal/entity/coverage_test.go
@@ -0,0 +1,122 @@
+package entity_test
+
+import (
+	"math/rand/v2"
+	"testing"
+
+	"github.com/samber/lo"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+
+	"github.com/Zxilly/go-size-analyzer/internal/entity"
+)
+
+func TestMergeCoverage(t *testing.T) {
+	cov1 := entity.AddrCoverage{
+		&entity.CoveragePart{
+			Pos:   &entity.AddrPos{Addr: 4096, Size: 256, Type: entity.AddrTypeData},
+			Addrs: []*entity.Addr{{}},
+		},
+	}
+	cov2 := entity.AddrCoverage{
+		&entity.CoveragePart{
+			Pos:   &entity.AddrPos{Addr: 4351, Size: 256, Type: entity.AddrTypeData},
+			Addrs: []*entity.Addr{{}},
+		},
+	}
+
+	expected := entity.AddrCoverage{
+		&entity.CoveragePart{
+			Pos:   &entity.AddrPos{Addr: 4096, Size: 511, Type: entity.AddrTypeData},
+			Addrs: nil,
+		},
+	}
+
+	result, err := entity.MergeAndCleanCoverage([]entity.AddrCoverage{cov1, cov2})
+	require.NoError(t, err)
+
+	// reset result Addrs
+	lo.ForEach(result, func(part *entity.CoveragePart, _ int) {
+		part.Addrs = nil
+	})
+
+	assert.Equal(t, expected, result)
+
+	cov3 := entity.AddrCoverage{
+		&entity.CoveragePart{
+			Pos:   &entity.AddrPos{Addr: 4096, Size: 256, Type: entity.AddrTypeText},
+			Addrs: []*entity.Addr{{}},
+		},
+	}
+	cov4 := entity.AddrCoverage{
+		&entity.CoveragePart{
+			Pos:   &entity.AddrPos{Addr: 4160, Size: 128, Type: entity.AddrTypeData}, // 与 cov3 有重叠
+			Addrs: []*entity.Addr{{}},
+		},
+	}
+
+	_, err = entity.MergeAndCleanCoverage([]entity.AddrCoverage{cov3, cov4})
+	assert.Error(t, err)
+}
+
+func FuzzMergeAndCleanCoverage(f *testing.F) {
+	f.Add(uint64(42), uint64(233))
+
+	f.Fuzz(func(t *testing.T, seed1, seed2 uint64) {
+		r := rand.New(rand.NewPCG(seed1, seed2)) //nolint:gosec
+
+		partCnt := rand.IntN(1024) + 2 //nolint:gosec
+
+		coves := make([]entity.AddrCoverage, 0, partCnt)
+
+		// we assume an addr space from 1 to 524288 (512KB),
+		// and each addr has a size from 1 to 65536 (64KB)
+
+		const maxAddr = 524288
+		const maxSize = 65536
+
+		for range partCnt {
+			addrPos := &entity.AddrPos{
+				Addr: r.Uint64N(maxAddr) + 1,
+				Size: r.Uint64N(maxSize),
+				Type: entity.AddrTypeData,
+			}
+
+			cov := entity.CoveragePart{
+				Pos: addrPos,
+				Addrs: []*entity.Addr{
+					{
+						AddrPos:    addrPos,
+						SourceType: entity.AddrSourceDwarf,
+					},
+				},
+			}
+
+			coves = append(coves, entity.AddrCoverage{&cov})
+		}
+
+		merged, err := entity.MergeAndCleanCoverage(coves)
+		require.NoError(t, err)
+
+		oldAddrSpace := make([]bool, maxAddr+maxSize+1)
+		newAddrSpace := make([]bool, maxAddr+maxSize+1)
+
+		for _, cov := range coves {
+			for _, part := range cov {
+				for i := part.Pos.Addr; i < part.Pos.Addr+part.Pos.Size; i++ {
+					oldAddrSpace[i] = true
+				}
+			}
+		}
+
+		for _, part := range merged {
+			for i := part.Pos.Addr; i < part.Pos.Addr+part.Pos.Size; i++ {
+				newAddrSpace[i] = true
+			}
+		}
+
+		for i := 1; i <= maxAddr; i++ {
+			assert.Equal(t, oldAddrSpace[i], newAddrSpace[i])
+		}
+	})
+}