fix(fpf): preserve routed seeds in tree drilldown

Author: m0n0x41d

internal/fpf/specsearch_drilldown.go

@@ -32,6 +32,7 @@ type drillDownBranch struct {
 	Path          []drillDownSection
 	Score         int
 	SeedOrder     int
+	SeedTier      string
 }
 
 func searchTreeDrillDown(db *sql.DB, query string, limit int) ([]SpecSearchResult, error) {
@@ -169,6 +170,7 @@ func buildDrillDownBranches(
 			Path:          path,
 			Score:         scoreDrillDownPath(path, queryTokens, seedOrder),
 			SeedOrder:     seedOrder,
+			SeedTier:      seed.Tier,
 		})
 	}
 
@@ -222,6 +224,16 @@ func sortDrillDownBranches(branches []drillDownBranch) {
 }
 
 func drillDownBranchLess(left, right drillDownBranch) bool {
+	leftSeedPriority := drillDownSeedPriority(left.SeedTier)
+	rightSeedPriority := drillDownSeedPriority(right.SeedTier)
+	if leftSeedPriority != rightSeedPriority {
+		return leftSeedPriority < rightSeedPriority
+	}
+
+	return drillDownBranchScoreLess(left, right)
+}
+
+func drillDownBranchScoreLess(left, right drillDownBranch) bool {
 	if left.Score != right.Score {
 		return left.Score > right.Score
 	}
@@ -234,6 +246,17 @@ func drillDownBranchLess(left, right drillDownBranch) bool {
 	return left.LeafPatternID < right.LeafPatternID
 }
 
+func drillDownSeedPriority(seedTier string) int {
+	switch seedTier {
+	case SpecSearchTierPattern:
+		return 0
+	case SpecSearchTierFTS:
+		return 1
+	default:
+		return 2
+	}
+}
+
 func buildDrillDownResults(branches []drillDownBranch, limit int) []SpecSearchResult {
 	if limit <= 0 {
 		limit = DefaultSpecSearchLimit

internal/fpf/tree_drilldown_test.go

@@ -62,6 +62,74 @@ func TestSearchSpecWithOptions_TreeModeReturnsLeafBeforeAncestors(t *testing.T)
 	}
 }
 
+func TestDrillDownRouteSeedsStayAheadOfFTSLeaves(t *testing.T) {
+	section := func(patternID string, parentPatternID string) drillDownSection {
+		return drillDownSection{
+			PatternID:       patternID,
+			Heading:         patternID,
+			Summary:         patternID,
+			ParentPatternID: parentPatternID,
+		}
+	}
+
+	branches := []drillDownBranch{
+		{
+			LeafPatternID: "A.6.3.CR",
+			Path: []drillDownSection{
+				section("A.6.3.CR", ""),
+			},
+			Score:     4,
+			SeedOrder: 0,
+			SeedTier:  SpecSearchTierPattern,
+		},
+		{
+			LeafPatternID: "E.17.EFP",
+			Path: []drillDownSection{
+				section("E.17.EFP", ""),
+			},
+			Score:     3,
+			SeedOrder: 1,
+			SeedTier:  SpecSearchTierPattern,
+		},
+		{
+			LeafPatternID: "A.6.3",
+			Path: []drillDownSection{
+				section("A.6.3", ""),
+			},
+			Score:     2,
+			SeedOrder: 2,
+			SeedTier:  SpecSearchTierPattern,
+		},
+		{
+			LeafPatternID: "A.6.3.RT",
+			Path: []drillDownSection{
+				section("A.6.3.RT", ""),
+			},
+			Score:     1,
+			SeedOrder: 3,
+			SeedTier:  SpecSearchTierPattern,
+		},
+		{
+			LeafPatternID: "A.6.3.CR:2",
+			Path: []drillDownSection{
+				section("A.6.3.CR:2", "A.6.3.CR"),
+				section("A.6.3.CR", ""),
+			},
+			Score:     1000,
+			SeedOrder: 4,
+			SeedTier:  SpecSearchTierFTS,
+		},
+	}
+
+	sortDrillDownBranches(branches)
+	results := buildDrillDownResults(branches, 4)
+	got := resultPatternIDs(results)
+	want := []string{"A.6.3.CR", "E.17.EFP", "A.6.3", "A.6.3.RT"}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("drill-down results = %v, want %v", got, want)
+	}
+}
+
 func TestSearchSpecWithOptions_DrillDownTierFilterKeepsOnlyExperimentalHits(t *testing.T) {
 	chunks := []SpecChunk{
 		{