fixup! fix(osgen): split unions out of ReqBodySiblings to fix empty-struct emission

Signed-off-by: Sean Chittenden <sean.chittenden@crowdstrike.com>

Author: sean-

cmd/osgen/emit/frag_dispatch_helpers_test.go

@@ -541,3 +541,109 @@ func TestUnionFromResponses(t *testing.T) {
 		})
 	}
 }
+
+func TestBulkInnerItemType(t *testing.T) {
+	t.Parallel()
+
+	tests := []struct {
+		name     string
+		resp     *ir.Type
+		regBuild func(reg *ir.TypeRegistry)
+		nilReg   bool
+		wantName string
+		wantOK   bool
+	}{
+		{
+			name:   "nil registry returns false",
+			resp:   newRespType("Bulk", ir.Field{GoName: "Items", GoType: "[]BulkItem"}),
+			nilReg: true,
+		},
+		{
+			name: "missing Items field returns false",
+			resp: newRespType("Bulk", ir.Field{GoName: "Errors", GoType: "bool"}),
+		},
+		{
+			name: "outer element type missing from registry returns false",
+			resp: newRespType("Bulk", ir.Field{GoName: "Items", GoType: "[]MissingOuter"}),
+		},
+		{
+			name: "outer with no pointer fields returns false",
+			resp: newRespType("Bulk", ir.Field{GoName: "Items", GoType: "[]NoPointers"}),
+			regBuild: func(reg *ir.TypeRegistry) {
+				regType(reg, &ir.Type{
+					Name:   "NoPointers",
+					Scope:  ir.ScopeLocal,
+					Fields: []ir.Field{{GoName: "Status", GoType: "int"}},
+				})
+			},
+		},
+		{
+			name: "first pointer field's target wins",
+			resp: newRespType("Bulk", ir.Field{GoName: "Items", GoType: "[]BulkItem"}),
+			regBuild: func(reg *ir.TypeRegistry) {
+				regType(reg, &ir.Type{
+					Name:  "BulkItem",
+					Scope: ir.ScopeLocal,
+					Fields: []ir.Field{
+						{GoName: "Errors", GoType: "bool", IsPointer: false},
+						{GoName: "Index", GoType: "*BulkRespItem", IsPointer: true},
+						{GoName: "Update", GoType: "*BulkRespItem", IsPointer: true},
+					},
+				})
+			},
+			wantName: "BulkRespItem",
+			wantOK:   true,
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			var reg *ir.TypeRegistry
+			if !tt.nilReg {
+				reg = newRegistry()
+				if tt.regBuild != nil {
+					tt.regBuild(reg)
+				}
+			}
+			got, ok := emit.BulkInnerItemType(tt.resp, reg)
+			require.Equal(t, tt.wantOK, ok)
+			require.Equal(t, tt.wantName, got)
+		})
+	}
+}
+
+func TestUnionFromResponses_FallbackBranches(t *testing.T) {
+	t.Parallel()
+
+	reg := newRegistry()
+	regType(reg, &ir.Type{
+		Name:   "ItemNotUnion",
+		Scope:  ir.ScopeLocal,
+		Fields: []ir.Field{{GoName: "Status", GoType: "int"}},
+	})
+
+	tests := []struct {
+		name string
+		resp *ir.Type
+	}{
+		{
+			name: "Responses element type missing from registry",
+			resp: newRespType("X", ir.Field{GoName: "Responses", GoType: "[]MissingType"}),
+		},
+		{
+			name: "Responses element type is registered but not a union",
+			resp: newRespType("X", ir.Field{GoName: "Responses", GoType: "[]ItemNotUnion"}),
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			t.Parallel()
+			unionName, success, errBranch := emit.UnionFromResponses(tt.resp, reg)
+			require.Empty(t, unionName)
+			require.Empty(t, success)
+			require.Empty(t, errBranch)
+		})
+	}
+}