codegen: CreateUpdateDelete test no longer creates an "Update" block if there's no updateable fields

pkg/codegen/modelgenerate/generate_testfile.go

@@ -67,26 +67,18 @@ func SampleValue(c pkgschema.Column, offset int) ast.Expr {
 }
 
 // UpdateTestFields returns the columns for which the test generator should assign its own
-// sample values, in the MakeXyz() factory and in the create/update test: the same columns
-// that GenerateSaveItemFunc's "update" branch writes to, minus foreign keys (which can't be
-// given plausible values here), the auto-managed "created_at"/"updated_at" columns, and the
-// soft-delete columns (which SoftDeleteXyz() manages).
+// sample values in MakeXyz() and the create/update test. It starts with Table.GetUpdateableColumns()
+// and removes fields the generated test should not assign directly: foreign keys and auto-managed
+// updated_at.
 func UpdateTestFields(tbl pkgschema.Table) (ret []pkgschema.Column) {
-	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
-	hasSoftDelete := tbl.HasSoftDelete()
-	for _, c := range tbl.Columns {
-		if c.Name == "rowid" || c.IsPrimaryKey || c.IsForeignKey {
-			continue
-		}
-		if c.Name == "created_at" && hasCreatedAt {
+	_, hasUpdatedAt := tbl.HasAutoTimestamps()
+	for _, c := range tbl.GetUpdateableColumns() {
+		if c.IsForeignKey {
 			continue
 		}
 		if c.Name == "updated_at" && hasUpdatedAt {
 			continue
 		}
-		if hasSoftDelete && (c.Name == "is_deleted" || c.Name == "deleted_at") {
-			continue
-		}
 		ret = append(ret, c)
 	}
 	return
@@ -486,39 +478,41 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					makeDeepEqual(testObj, testObj2),
 				)
 
-				stmts = append(stmts,
-					BlankLine(),
-					Comment("Update"),
-				)
+				if len(tbl.GetUpdateableColumns()) > 0 { // Skip if no mutable fields
+					stmts = append(stmts,
+						BlankLine(),
+						Comment("Update"),
+					)
 
-				// item.Description = <sample value, offset 2>
-				// ...one assignment per updatable field
-				for _, c := range updateTestFields {
-					stmts = append(stmts, &ast.AssignStmt{
-						Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent(c.GoFieldName())}},
-						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{SampleValue(c, 2)},
-					})
+					// item.Description = <sample value, offset 2>
+					// ...one assignment per updatable field
+					for _, c := range updateTestFields {
+						stmts = append(stmts, &ast.AssignStmt{
+							Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent(c.GoFieldName())}},
+							Tok: token.ASSIGN,
+							Rhs: []ast.Expr{SampleValue(c, 2)},
+						})
+					}
+
+					stmts = append(stmts,
+						// TestDB.SaveItem(&item)
+						&ast.ExprStmt{X: &ast.CallExpr{
+							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Save" + tbl.GoTypeName)},
+							Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: testObj}},
+						}},
+
+						// item2 = must.Get(TestDB.GetItemByID(item.ID))
+						&ast.AssignStmt{
+							Lhs: []ast.Expr{testObj2},
+							Tok: token.ASSIGN,
+							Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
+						},
+
+						// if deep.Equal(...) {...}
+						makeDeepEqual(testObj, testObj2),
+					)
 				}
 
-				stmts = append(stmts,
-					// TestDB.SaveItem(&item)
-					&ast.ExprStmt{X: &ast.CallExpr{
-						Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Save" + tbl.GoTypeName)},
-						Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: testObj}},
-					}},
-
-					// item2 = must.Get(TestDB.GetItemByID(item.ID))
-					&ast.AssignStmt{
-						Lhs: []ast.Expr{testObj2},
-						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
-					},
-
-					// if deep.Equal(...) {...}
-					makeDeepEqual(testObj, testObj2),
-				)
-
 				indexGets, hasIndexedGets := []ast.Stmt{
 					BlankLine(),
 					Comment("Indexed lookups"),