codegen: generate getters for compound indexes

.gitea/workflows/CI.yaml

@@ -1,6 +1,6 @@
 name: CI
 
-on: [push]
+on: [push, workflow_dispatch]
 
 jobs:
   # These steps build the `gas` docker image.

.golangci.yaml

@@ -60,8 +60,6 @@ linters:
         - -ST1000 # Re-enable this once we have docstrings
         - -ST1003 # I like snake_case
         - -ST1013 # HTTP status codes are shorter and more readable than names
-      dot-import-whitelist:
-        - "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
   exclusions:
     generated: lax # Don't lint generated files
     paths:

cmd/subcmd_generate_models.go

@@ -6,11 +6,12 @@ import (
 	"go/ast"
 	"go/token"
 	"os"
+	"slices"
 
 	"github.com/spf13/cobra"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen/modelgenerate"
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
 )
 
@@ -23,22 +24,22 @@ var generate_model = &cobra.Command{
 	Args: cobra.ExactArgs(1),
 
 	RunE: func(cmd *cobra.Command, args []string) error {
-		path := Must(cmd.Flags().GetString("schema"))
-		modname := Must(cmd.Flags().GetString("modname"))
+		path := must.Get(cmd.Flags().GetString("schema"))
+		modname := must.Get(cmd.Flags().GetString("modname"))
 		sql, err := os.ReadFile(path)
 		if err != nil {
 			return fmt.Errorf("reading path %s: %w", path, err)
 		}
 		db := schema.InitDB(string(sql))
-		schema := schema.SchemaFromDB(db)
-		table, isOk := schema.Tables[args[0]]
+		sch := schema.SchemaFromDB(db)
+		table, isOk := sch.Tables[args[0]]
 		if !isOk {
 			return ErrNoSuchTable
 		}
 
-		if Must(cmd.Flags().GetBool("test")) {
-			file2 := modelgenerate.GenerateModelTestAST(table, schema, modname)
-			PanicIf(modelgenerate.FprintWithComments(os.Stdout, file2))
+		if must.Get(cmd.Flags().GetBool("test")) {
+			file2 := modelgenerate.GenerateModelTestAST(table, sch, modname)
+			must.Do(modelgenerate.FprintWithComments(os.Stdout, file2))
 		} else {
 			decls := []ast.Decl{
 				&ast.GenDecl{
@@ -51,10 +52,9 @@ var generate_model = &cobra.Command{
 							Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"`},
 						},
 						&ast.ImportSpec{
-							Name: ast.NewIdent("."),
 							Path: &ast.BasicLit{
 								Kind:  token.STRING,
-								Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"`,
+								Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"`,
 							},
 						},
 					},
@@ -78,13 +78,23 @@ var generate_model = &cobra.Command{
 					modelgenerate.GenerateGetItemByIDFunc(table),
 				)
 			}
-			for _, index := range schema.Indexes {
+			for _, index := range sch.Indexes {
 				if index.TableName != table.TableName {
 					// Skip indexes on other tables
 					continue
 				}
-				if index.IsUnique && len(index.Columns) == 1 {
-					decls = append(decls, modelgenerate.GenerateGetItemByUniqColFunc(table, table.GetColumnByName(index.Columns[0])))
+				if slices.Contains(index.Columns, "") {
+					// Skip expression indexes; there's no way to resolve an expression to a real column
+					continue
+				}
+				cols := make([]schema.Column, len(index.Columns))
+				for i, colName := range index.Columns {
+					cols[i] = table.GetColumnByName(colName)
+				}
+				if index.IsUnique {
+					decls = append(decls, modelgenerate.GenerateGetItemBy(table, cols))
+				} else {
+					decls = append(decls, modelgenerate.GenerateGetItemsBy(table, cols))
 				}
 			}
 			decls = append(decls, modelgenerate.GenerateGetAllItemsFunc(table))
@@ -94,7 +104,7 @@ var generate_model = &cobra.Command{
 				Decls: decls,
 			}
 
-			PanicIf(modelgenerate.FprintWithComments(os.Stdout, file))
+			must.Do(modelgenerate.FprintWithComments(os.Stdout, file))
 		}
 
 		return nil

cmd/subcmd_init.go

@@ -9,7 +9,7 @@ import (
 	"github.com/spf13/cobra"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/codegen"
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 )
 
 var cmd_init = &cobra.Command{
@@ -23,11 +23,11 @@ var cmd_init = &cobra.Command{
 		var target string
 		if len(args) != 0 {
 			target = args[0]
-			PanicIf(os.MkdirAll(target, 0o755))
-			PanicIf(os.Chdir(target))
+			must.Do(os.MkdirAll(target, 0o755))
+			must.Do(os.Chdir(target))
 		} else {
 			// Default to current directory (".")
-			target = Must(os.Getwd())
+			target = must.Get(os.Getwd())
 		}
 
 		// Get all the config values
@@ -41,9 +41,9 @@ var cmd_init = &cobra.Command{
 			}
 		}
 		pkg_opts := codegen.PkgOpts{
-			ModuleName: Must(cmd.Flags().GetString("module")),
-			DBFilename: Must(cmd.Flags().GetString("db")),
-			BinaryName: Must(cmd.Flags().GetString("binary")),
+			ModuleName: must.Get(cmd.Flags().GetString("module")),
+			DBFilename: must.Get(cmd.Flags().GetString("db")),
+			BinaryName: must.Get(cmd.Flags().GetString("binary")),
 		}
 		if pkg_opts.ModuleName == "" {
 			pkg_opts.ModuleName = filepath.Base(target)

ops/test.sh

@@ -0,0 +1,3 @@
+#!/bin/sh
+
+go test -tags fts5 ./...

pkg/codegen/modelgenerate/ast_helpers.go

@@ -27,10 +27,18 @@ const (
 // we don't have to do that.
 var TrailingComments = map[ast.Node]string{}
 
-// mustCall wraps a call expression in Must(...), producing AST for Must(inner).
+// mustCall wraps a call expression in must.Get(...), producing AST for must.Get(inner).
 func mustCall(inner ast.Expr) *ast.CallExpr {
 	return &ast.CallExpr{
-		Fun:  ast.NewIdent("Must"),
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Get")},
+		Args: []ast.Expr{inner},
+	}
+}
+
+// doCall wraps a call expression in must.Do(...), producing AST for must.Do(inner).
+func doCall(inner ast.Expr) *ast.CallExpr {
+	return &ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Do")},
 		Args: []ast.Expr{inner},
 	}
 }
@@ -73,7 +81,7 @@ func FprintWithComments(w io.Writer, file *ast.File) error {
 	fset = token.NewFileSet()
 	parsed, err := parser.ParseFile(fset, "", buf.Bytes(), parser.ParseComments)
 	if err != nil {
-		return fmt.Errorf("re-parsing pretty-print: %w", err)
+		return fmt.Errorf("re-parsing pretty-print: %w\n\n%s", err, buf.String())
 	}
 
 	// Parallel walk: apply TrailingComments from the side map.

pkg/codegen/modelgenerate/generate_model.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"slices"
 	"strings"
 
 	"github.com/jinzhu/inflection"
@@ -23,7 +24,7 @@ var (
 )
 
 func SQLFieldsConstIdent(tbl schema.Table) *ast.Ident {
-	return ast.NewIdent(strings.ToLower(tbl.GoTypeName) + "SQLFields")
+	return ast.NewIdent(strings.ToLower(tbl.GoTypeName[:1]) + tbl.GoTypeName[1:] + "SQLFields")
 }
 
 // GoTypeForColumn returns a type expression for this column.
@@ -53,20 +54,48 @@ func GoTypeForColumn(c schema.Column) ast.Expr {
 	}
 }
 
-func PanicIfRowsAffected(tbl schema.Table) *ast.IfStmt {
-	return &ast.IfStmt{
-		Cond: &ast.BinaryExpr{
+// MustBeRowsAffected produces an AST for a `must.Be(...)` call asserting that exactly one row
+// was affected by the preceding statement, e.g.:
+//
+//	must.Be(must.Get(result.RowsAffected()) == 1, "%w: Food ID=%d", ErrNotInDB, f.ID)
+//
+// For "without rowid" tables, the message includes the table's primary key column(s) instead of ID.
+func MustBeRowsAffected(tbl schema.Table) *ast.ExprStmt {
+	pkParts := []string{}
+	pkArgs := []ast.Expr{}
+	if tbl.IsWithoutRowid {
+		for _, col := range tbl.PrimaryKeyColumns() {
+			verb := "%v"
+			if col.Type == "integer" || col.Type == "int" || col.IsNonCodeTableForeignKey() {
+				verb = "%d"
+			}
+			pkParts = append(pkParts, fmt.Sprintf("%s=%s", col.Name, verb))
+			pkArgs = append(pkArgs, &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(col.GoFieldName())})
+		}
+	} else {
+		pkParts = append(pkParts, "ID=%d")
+		pkArgs = append(pkArgs, &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("ID")})
+	}
+
+	msg := fmt.Sprintf("%%w: %s %s", tbl.GoTypeName, strings.Join(pkParts, ", "))
+
+	args := append([]ast.Expr{
+		&ast.BinaryExpr{
 			X: mustCall(&ast.CallExpr{
 				Fun:  &ast.SelectorExpr{X: ast.NewIdent("result"), Sel: ast.NewIdent("RowsAffected")},
 				Args: []ast.Expr{},
 			}),
-			Op: token.NEQ,
+			Op: token.EQL,
 			Y:  &ast.BasicLit{Kind: token.INT, Value: "1"},
 		},
-		Body: &ast.BlockStmt{List: []ast.Stmt{
-			&ast.ExprStmt{X: &ast.CallExpr{Fun: ast.NewIdent("panic"), Args: []ast.Expr{ast.NewIdent(tbl.VarName)}}},
-		}},
-	}
+		&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", msg)},
+		ast.NewIdent("ErrNotInDB"),
+	}, pkArgs...)
+
+	return &ast.ExprStmt{X: &ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: ast.NewIdent("must"), Sel: ast.NewIdent("Be")},
+		Args: args,
+	}}
 }
 
 // ---------------
@@ -161,9 +190,21 @@ func buildFKCheckLambda(tbl schema.Table) (*ast.AssignStmt, bool) {
 							structFieldName := col.GoFieldName()
 							structField := &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent(structFieldName)}
 
+							ret = append(ret, func() ast.Stmt {
+								// Wrap nullable FKs in "if a.val != 0 { ... }"
+								wrap := func(input ast.Stmt) ast.Stmt {
+									if col.IsNullableForeignKey() {
+										return &ast.IfStmt{
+											Cond: &ast.BinaryExpr{X: structField, Op: token.NEQ, Y: &ast.BasicLit{Kind: token.INT, Value: "0"}},
+											Body: &ast.BlockStmt{List: []ast.Stmt{input}},
+										}
+									} else {
+										return input
+									}
+								}
 								if col.IsNonCodeTableForeignKey() {
 									// Real foreign key; look up referent by ID to see if it exists
-								ret = append(ret, &ast.IfStmt{
+									return wrap(&ast.IfStmt{
 										Init: &ast.AssignStmt{
 											Lhs: []ast.Expr{ast.NewIdent("_"), ast.NewIdent("err")},
 											Tok: token.DEFINE,
@@ -197,7 +238,7 @@ func buildFKCheckLambda(tbl schema.Table) (*ast.AssignStmt, bool) {
 									})
 								} else {
 									// Code table value.  Query the table to see if it exists
-								ret = append(ret, &ast.IfStmt{
+									return wrap(&ast.IfStmt{
 										Init: &ast.AssignStmt{
 											Lhs: []ast.Expr{ast.NewIdent("err")},
 											Tok: token.DEFINE,
@@ -234,6 +275,7 @@ func buildFKCheckLambda(tbl schema.Table) (*ast.AssignStmt, bool) {
 										},
 									})
 								}
+							}())
 						}
 						// final return nil
 						ret = append(ret, &ast.ReturnStmt{Results: []ast.Expr{ast.NewIdent("nil")}})
@@ -320,7 +362,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 					},
 				}
 				if !hasFks {
-					// No foreign key checking needed; just use `Must` for brevity
+					// No foreign key checking needed; just use `must.Get` for brevity
 					return []ast.Stmt{&ast.AssignStmt{
 						Lhs: []ast.Expr{ast.NewIdent("result")},
 						Tok: token.DEFINE,
@@ -386,8 +428,26 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 			}
 
 			if tbl.IsWithoutRowid {
+				if hasCreatedAt {
+					// Auto-timestamps: created_at.  Don't overwrite existing timestamps (e.g., data import / migrations)
+					ret = append(ret, &ast.IfStmt{
+						Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{
+							X:   &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")},
+							Sel: ast.NewIdent("IsZero"),
+						}},
+						Body: &ast.BlockStmt{
+							List: []ast.Stmt{
+								&ast.AssignStmt{
+									Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")}},
+									Tok: token.ASSIGN,
+									Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+								},
+							},
+						},
+					})
+				}
 				ret = append(ret, namedExecStmt(upsertStmt)...)
-				ret = append(ret, PanicIfRowsAffected(tbl))
+				ret = append(ret, MustBeRowsAffected(tbl))
 			} else {
 				// if item.ID == 0 {...} else {...}
 				ret = append(ret, &ast.IfStmt{
@@ -403,10 +463,21 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 								ret1 := []ast.Stmt{Comment("Do create")}
 								if hasCreatedAt {
 									// Auto-timestamps: created_at
-									ret1 = append(ret1, &ast.AssignStmt{
+									ret1 = append(ret1, &ast.IfStmt{
+										// Don't overwrite existing timestamps.  This is useful for various reasons, e.g., data import / migrations
+										Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{
+											X:   &ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")},
+											Sel: ast.NewIdent("IsZero"),
+										}},
+										Body: &ast.BlockStmt{
+											List: []ast.Stmt{
+												&ast.AssignStmt{
 													Lhs: []ast.Expr{&ast.SelectorExpr{X: ast.NewIdent(tbl.VarName), Sel: ast.NewIdent("CreatedAt")}},
 													Tok: token.ASSIGN,
 													Rhs: []ast.Expr{&ast.CallExpr{Fun: ast.NewIdent("TimestampNow"), Args: []ast.Expr{}}},
+												},
+											},
+										},
 									})
 								}
 								return append(ret1, namedExecStmt(insertStmt)...)
@@ -430,7 +501,7 @@ func GenerateSaveItemFunc(tbl schema.Table) *ast.FuncDecl {
 							[]ast.Stmt{Comment("Do update")},
 							append(
 								namedExecStmt(updateStmt),
-								PanicIfRowsAffected(tbl),
+								MustBeRowsAffected(tbl),
 							)...,
 						),
 					},
@@ -469,15 +540,50 @@ func getByIDFuncName(tblname string) string {
 	return "Get" + schema.TypenameFromTablename(tblname) + "ByID"
 }
 
+// paramNamesFor picks parameter identifiers for a `Get...By()` function's columns.
+// A single column always uses the short GoVarName() form (e.g. "name").  For multiple
+// columns, GoVarName() is preferred for readability, but if two or more of the given
+// columns would produce the same short name (e.g. two foreign keys that both abbreviate
+// to "uID"), the longer, unambiguous LongGoVarName() form is used for all of them instead,
+// since a collision there would produce invalid (duplicate-parameter) Go code.
+func paramNamesFor(cols []schema.Column) []string {
+	names := make([]string, len(cols))
+	if len(cols) == 1 {
+		names[0] = cols[0].GoVarName()
+		return names
+	}
+
+	hasConflict := false
+	for i, c := range cols {
+		names[i] = c.GoVarName()
+		if slices.Contains(names[:i], names[i]) {
+			hasConflict = true
+			break
+		}
+	}
+	if !hasConflict {
+		return names
+	}
+	for i, c := range cols {
+		names[i] = c.LongGoVarName()
+	}
+	return names
+}
+
+// GenerateGetItemBy produces an AST for a `GetXyzByCol1AndCol2...()` function that returns
+// the single item matching an exact-match lookup over the given columns (or ErrNotInDB).
+// Used for unique indexes (single- or multi-column) and for "without rowid" tables' primary keys.
 func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
+	paramNames := paramNamesFor(cols)
+
 	colNames := []string{}
 	funcNameSuffix := []string{}
 	funcParams := &ast.FieldList{List: []*ast.Field{}}
 	sqlParams := []ast.Expr{}
-	for _, col := range cols {
-		funcParam := ast.NewIdent(col.LongGoVarName())
+	for i, col := range cols {
+		funcParam := ast.NewIdent(paramNames[i])
 		funcParams.List = append(funcParams.List, &ast.Field{Names: []*ast.Ident{funcParam}, Type: GoTypeForColumn(col)})
-		colNames = append(colNames, fmt.Sprintf("%s = :%s", col.Name, col.Name))
+		colNames = append(colNames, fmt.Sprintf("%s = ?", col.Name))
 		funcNameSuffix = append(funcNameSuffix, col.GoFieldName())
 		sqlParams = append(sqlParams, funcParam)
 	}
@@ -489,7 +595,7 @@ func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
 			Y:  SQLFieldsConstIdent(tbl),
 		},
 		Op: token.ADD,
-		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s = ?\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
+		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
 	}
 
 	return &ast.FuncDecl{
@@ -515,7 +621,8 @@ func GenerateGetItemBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
 				&ast.IfStmt{
 					Cond: &ast.CallExpr{
 						Fun:  &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")},
-						Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}}},
+						Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}},
+					},
 					Body: &ast.BlockStmt{List: []ast.Stmt{&ast.ReturnStmt{Results: []ast.Expr{&ast.CompositeLit{Type: ast.NewIdent(tbl.GoTypeName)}, ast.NewIdent("ErrNotInDB")}}}},
 				},
 				&ast.ReturnStmt{},
@@ -564,10 +671,33 @@ func GenerateGetItemByIDFunc(tbl schema.Table) *ast.FuncDecl {
 	}
 }
 
-// GenerateGetItemByUniqColFunc produces an AST for the `GetXyzByID()` function.
-// E.g., a table with `table.TypeName = "foods"` will produce a "GetFoodByID()" function.
+// GenerateGetItemByUniqColFunc produces an AST for the `GetXyzByCol()` function, for a unique
+// index on a single column.
+// E.g., a table with `table.TypeName = "foods"` will produce a "GetFoodByName()" function.
 func GenerateGetItemByUniqColFunc(tbl schema.Table, col schema.Column) *ast.FuncDecl {
-	// Use the xyzSQLFields constant in the select query
+	return GenerateGetItemBy(tbl, []schema.Column{col})
+}
+
+// GenerateGetItemsBy produces an AST for a `GetXyzsByCol1AndCol2...()` function that returns
+// all items matching an exact-match lookup over the given columns.  Used for non-unique
+// indexes (single- or multi-column).
+// E.g., a table with `table.TableName = "foods"` and a non-unique index on "category" will
+// produce a "GetFoodsByCategory(category string) []Food" function.
+func GenerateGetItemsBy(tbl schema.Table, cols []schema.Column) *ast.FuncDecl {
+	paramNames := paramNamesFor(cols)
+
+	colNames := []string{}
+	funcNameSuffix := []string{}
+	funcParams := &ast.FieldList{List: []*ast.Field{}}
+	sqlParams := []ast.Expr{}
+	for i, col := range cols {
+		funcParam := ast.NewIdent(paramNames[i])
+		funcParams.List = append(funcParams.List, &ast.Field{Names: []*ast.Ident{funcParam}, Type: GoTypeForColumn(col)})
+		colNames = append(colNames, fmt.Sprintf("%s = ?", col.Name))
+		funcNameSuffix = append(funcNameSuffix, col.GoFieldName())
+		sqlParams = append(sqlParams, funcParam)
+	}
+
 	selectExpr := &ast.BinaryExpr{
 		X: &ast.BinaryExpr{
 			X:  &ast.BasicLit{Kind: token.STRING, Value: "`\n\t    select `"},
@@ -575,40 +705,40 @@ func GenerateGetItemByUniqColFunc(tbl schema.Table, col schema.Column) *ast.Func
 			Y:  SQLFieldsConstIdent(tbl),
 		},
 		Op: token.ADD,
-		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s = ?\n\t`", tbl.TableName, col.Name)},
+		Y:  &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("`\n\t      from %s\n\t     where %s\n\t`", tbl.TableName, strings.Join(colNames, " and "))},
 	}
 
-	param := ast.NewIdent(col.GoVarName())
+	selectCall := doCall(&ast.CallExpr{
+		Fun:  &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Select")},
+		Args: append([]ast.Expr{&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")}, selectExpr}, sqlParams...),
+	})
 
 	return &ast.FuncDecl{
 		Recv: dbRecv,
-		Name: ast.NewIdent("Get" + schema.TypenameFromTablename(tbl.TableName) + "By" + col.GoFieldName()),
+		Name: ast.NewIdent("Get" + inflection.Plural(schema.TypenameFromTablename(tbl.TableName)) + "By" + strings.Join(funcNameSuffix, "And")),
 		Type: &ast.FuncType{
-			Params: &ast.FieldList{List: []*ast.Field{
-				{Names: []*ast.Ident{param}, Type: GoTypeForColumn(col)},
-			}},
+			Params: funcParams,
 			Results: &ast.FieldList{List: []*ast.Field{
-				{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: ast.NewIdent(tbl.GoTypeName)},
-				{Names: []*ast.Ident{ast.NewIdent("err")}, Type: ast.NewIdent("error")},
+				{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: &ast.ArrayType{Elt: ast.NewIdent(tbl.GoTypeName)}},
 			}},
 		},
 		Body: &ast.BlockStmt{
 			List: []ast.Stmt{
-				&ast.AssignStmt{
-					Lhs: []ast.Expr{ast.NewIdent("err")},
-					Tok: token.ASSIGN,
-					Rhs: []ast.Expr{&ast.CallExpr{Fun: &ast.SelectorExpr{X: dbDB, Sel: ast.NewIdent("Get")}, Args: []ast.Expr{&ast.UnaryExpr{Op: token.AND, X: ast.NewIdent("ret")}, selectExpr, param}}},
-				},
-				&ast.IfStmt{
-					Cond: &ast.CallExpr{Fun: &ast.SelectorExpr{X: ast.NewIdent("errors"), Sel: ast.NewIdent("Is")}, Args: []ast.Expr{ast.NewIdent("err"), &ast.SelectorExpr{X: ast.NewIdent("sql"), Sel: ast.NewIdent("ErrNoRows")}}},
-					Body: &ast.BlockStmt{List: []ast.Stmt{&ast.ReturnStmt{Results: []ast.Expr{&ast.CompositeLit{Type: ast.NewIdent(tbl.GoTypeName)}, ast.NewIdent("ErrNotInDB")}}}},
-				},
+				&ast.ExprStmt{X: selectCall},
 				&ast.ReturnStmt{},
 			},
 		},
 	}
 }
 
+// GenerateGetItemsByColFunc produces an AST for the `GetXyzsByCol()` function, for a non-unique
+// index on a single column.
+// E.g., a table with `table.TableName = "foods"` and a non-unique index on "category" will
+// produce a "GetFoodsByCategory(category string) []Food" function.
+func GenerateGetItemsByColFunc(tbl schema.Table, col schema.Column) *ast.FuncDecl {
+	return GenerateGetItemsBy(tbl, []schema.Column{col})
+}
+
 // GenerateGetAllItemsFunc produces an AST for the `GetAllXyzs()` function.
 // E.g., a table with `table.TypeName = "foods"` will produce a "GetAllFoods()" function.
 func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
@@ -617,10 +747,7 @@ func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
 		{Names: []*ast.Ident{ast.NewIdent("ret")}, Type: &ast.ArrayType{Elt: ast.NewIdent(tbl.GoTypeName)}},
 	}}
 
-	selectCall := &ast.CallExpr{
-		Fun: ast.NewIdent("PanicIf"),
-		Args: []ast.Expr{
-			&ast.CallExpr{
+	selectCall := doCall(&ast.CallExpr{
 		Fun: &ast.SelectorExpr{
 			X:   dbDB,
 			Sel: ast.NewIdent("Select"),
@@ -637,9 +764,7 @@ func GenerateGetAllItemsFunc(tbl schema.Table) *ast.FuncDecl {
 				Y:  &ast.BasicLit{Kind: token.STRING, Value: "` from " + tbl.TableName + "`"},
 			},
 		},
-			},
-		},
-	}
+	})
 
 	funcBody := &ast.BlockStmt{
 		List: []ast.Stmt{
@@ -682,7 +807,7 @@ func GenerateDeleteItemFunc(tbl schema.Table) *ast.FuncDecl {
 					},
 				})},
 			},
-			PanicIfRowsAffected(tbl),
+			MustBeRowsAffected(tbl),
 		},
 	}
 

pkg/codegen/modelgenerate/generate_testfile.go

@@ -4,6 +4,8 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"slices"
+	"strings"
 
 	"github.com/jinzhu/inflection"
 
@@ -11,6 +13,80 @@ import (
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
+// SampleValue returns a deterministic value of the appropriate type for the given column.
+func SampleValue(c pkgschema.Column, offset int) ast.Expr {
+	switch c.Type {
+	case "integer", "int":
+		if strings.HasPrefix(c.Name, "is_") || strings.HasPrefix(c.Name, "has_") {
+			// Boolean case
+			if offset%2 == 0 {
+				return ast.NewIdent("false")
+			}
+			return ast.NewIdent("true")
+		} else if strings.HasSuffix(c.Name, "_at") {
+			// Timestamp case
+			return &ast.CallExpr{
+				Fun: ast.NewIdent("TimestampFromUnix"),
+				Args: []ast.Expr{
+					&ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%d", 10000+offset)},
+				},
+			}
+		} else {
+			// Regular integer case
+			return &ast.BasicLit{Kind: token.INT, Value: fmt.Sprintf("%d", 10+offset)}
+		}
+	case "text":
+		if offset == 0 {
+			return &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", "asdf")}
+		}
+		return &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", fmt.Sprintf("asdf%d", offset))}
+	case "real":
+		return &ast.BasicLit{Kind: token.FLOAT, Value: fmt.Sprintf("%.2f", 1.23+float64(offset))}
+	case "blob":
+		return &ast.CompositeLit{
+			Type: &ast.ArrayType{
+				Elt: ast.NewIdent("byte"),
+			},
+			Elts: func() []ast.Expr {
+				ret := []ast.Expr{
+					&ast.BasicLit{Kind: token.INT, Value: "72"},  // 'H'
+					&ast.BasicLit{Kind: token.INT, Value: "105"}, // 'i'
+					&ast.BasicLit{Kind: token.INT, Value: "33"},  // '!'
+				}
+				for range offset {
+					ret = append(ret,
+						&ast.BasicLit{Kind: token.INT, Value: "33"}, // '!'
+					)
+				}
+				return ret
+			}(),
+		}
+	default:
+		panic("Unrecognized sqlite column type: " + c.Type)
+	}
+}
+
+// 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) and the auto-managed "created_at"/"updated_at" columns.
+func UpdateTestFields(tbl pkgschema.Table) (ret []pkgschema.Column) {
+	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+	for _, c := range tbl.Columns {
+		if c.Name == "rowid" || c.IsPrimaryKey || c.IsForeignKey {
+			continue
+		}
+		if c.Name == "created_at" && hasCreatedAt {
+			continue
+		}
+		if c.Name == "updated_at" && hasUpdatedAt {
+			continue
+		}
+		ret = append(ret, c)
+	}
+	return
+}
+
 // GenerateModelTestAST produces an AST for a starter test file for a given model.
 func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodName string) *ast.File {
 	packageName := "db"
@@ -18,6 +94,9 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 
 	makeHelperName := ast.NewIdent("Make" + tbl.GoTypeName)
 
+	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+	updateTestFields := UpdateTestFields(tbl)
+
 	// func MakeItem() Item { return Item{} }
 	makeItemFunc := &ast.FuncDecl{
 		Name: makeHelperName,
@@ -35,24 +114,15 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					Results: []ast.Expr{
 						&ast.CompositeLit{
 							Type: ast.NewIdent(tbl.GoTypeName),
-							Elts: []ast.Expr{
-								&ast.KeyValueExpr{
-									Key: ast.NewIdent("Data"),
-									Value: &ast.CompositeLit{
-										Type: &ast.ArrayType{
-											Elt: ast.NewIdent("byte"),
-										},
-										Elts: []ast.Expr{},
-									},
-								},
-								&ast.KeyValueExpr{
-									Key: ast.NewIdent("Description"),
-									Value: &ast.BasicLit{
-										Kind:  token.STRING,
-										Value: `""`,
-									},
-								},
-							},
+							Elts: func() (ret []ast.Expr) {
+								for _, c := range updateTestFields {
+									ret = append(ret, &ast.KeyValueExpr{
+										Key:   ast.NewIdent(c.GoFieldName()),
+										Value: SampleValue(c, 0),
+									})
+								}
+								return
+							}(),
 						},
 					},
 				},
@@ -62,12 +132,32 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 
 	testObj := ast.NewIdent(textutils.CamelToPascal(tbl.GoTypeName))
 	testObj2 := ast.NewIdent(textutils.CamelToPascal(tbl.GoTypeName) + "2")
-	fieldName := ast.NewIdent("Description") // TODO
-	description1 := "an item"
-	description2 := "a big item"
 	testDB := ast.NewIdent("TestDB")
 
-	hasCreatedAt, hasUpdatedAt := tbl.HasAutoTimestamps()
+	// getItemByPKCall builds a call to this table's primary-key getter (e.g. `TestDB.GetItemByID(item.ID)`,
+	// or `TestDB.GetItemByColAAndColB(item.ColA, item.ColB)` for "without rowid" tables with a
+	// compound primary key), matching whatever GenerateGetItemByIDFunc/GenerateGetItemBy generated.
+	getItemByPKCall := func(obj *ast.Ident) *ast.CallExpr {
+		if !tbl.IsWithoutRowid {
+			// Normal rowid table: use GetXyzByID
+			return &ast.CallExpr{
+				Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
+				Args: []ast.Expr{&ast.SelectorExpr{X: obj, Sel: ast.NewIdent("ID")}},
+			}
+		} else {
+			// "Without rowid" table: use the primary key "GetItemByBlahBlah" query func
+			funcNameSuffix := []string{}
+			args := []ast.Expr{}
+			for _, c := range tbl.PrimaryKeyColumns() {
+				funcNameSuffix = append(funcNameSuffix, c.GoFieldName())
+				args = append(args, &ast.SelectorExpr{X: obj, Sel: ast.NewIdent(c.GoFieldName())})
+			}
+			return &ast.CallExpr{
+				Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "By" + strings.Join(funcNameSuffix, "And"))},
+				Args: args,
+			}
+		}
+	}
 
 	makeDeepEqual := func(obj1 *ast.Ident, obj2 *ast.Ident) *ast.IfStmt {
 		return &ast.IfStmt{
@@ -236,23 +326,22 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						Tok: token.DEFINE,
 						Rhs: []ast.Expr{&ast.CallExpr{Fun: makeHelperName, Args: nil}},
 					},
-					// item.Description = "an item"
-					&ast.AssignStmt{
+					// item.Description = <sample value, offset 1>
+					// ...one assignment per updatable field
+				}
+				for _, c := range updateTestFields {
+					stmts = append(stmts, &ast.AssignStmt{
 						Lhs: []ast.Expr{
 							&ast.SelectorExpr{
 								X:   testObj,
-								Sel: ast.NewIdent("Description"),
+								Sel: ast.NewIdent(c.GoFieldName()),
 							},
 						},
 						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{
-							&ast.BasicLit{
-								Kind:  token.STRING,
-								Value: fmt.Sprintf("%q", description1),
-							},
-						},
-					},
-
+						Rhs: []ast.Expr{SampleValue(c, 1)},
+					})
+				}
+				stmts = append(stmts,
 					// TestDB.SaveItem(&item), possibly with error check
 					&ast.ExprStmt{X: func() *ast.CallExpr {
 						mainExpr := &ast.CallExpr{
@@ -268,12 +357,14 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						}
 						return mainExpr
 					}()},
+				)
 
 				// require.NotZero(t, item.ID)
-					&ast.ExprStmt{X: &ast.CallExpr{
+				if !tbl.IsWithoutRowid { // non-rowid tables don't get an ID
+					stmts = append(stmts, &ast.ExprStmt{X: &ast.CallExpr{
 						Fun:  &ast.SelectorExpr{X: ast.NewIdent("require"), Sel: ast.NewIdent("NotZero")},
 						Args: []ast.Expr{ast.NewIdent("t"), &ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-					}},
+					}})
 				}
 
 				// After create: assert timestamps are set
@@ -288,14 +379,11 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					BlankLine(),
 					Comment("Load"),
 
-					// item2 := Must(TestDB.GetItemByID(item.ID))
+					// item2 := must.Get(TestDB.GetItemByID(item.ID))
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{testObj2},
 						Tok: token.DEFINE,
-						Rhs: []ast.Expr{mustCall(&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						})},
+						Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
 					},
 
 					// if deep.Equal(...) {...}
@@ -305,28 +393,30 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 				stmts = append(stmts,
 					BlankLine(),
 					Comment("Update"),
+				)
 
-					// item.Description = "a big item"
-					&ast.AssignStmt{
-						Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: fieldName}},
+				// 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{&ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf("%q", description2)}},
-					},
+						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(TestDB.GetItemByID(item.ID))
+					// item2 = must.Get(TestDB.GetItemByID(item.ID))
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{testObj2},
 						Tok: token.ASSIGN,
-						Rhs: []ast.Expr{mustCall(&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						})},
+						Rhs: []ast.Expr{mustCall(getItemByPKCall(testObj))},
 					},
 
 					// if deep.Equal(...) {...}
@@ -343,8 +433,21 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						// Skip indexes on other tables
 						continue
 					}
-					if index.IsUnique && len(index.Columns) == 1 {
-						col := tbl.GetColumnByName(index.Columns[0])
+					if slices.Contains(index.Columns, "") {
+						// Skip expression indexes; there's no way to resolve an expression to a real column
+						continue
+					}
+					cols := make([]pkgschema.Column, len(index.Columns))
+					nameParts := make([]string, len(index.Columns))
+					callArgs := make([]ast.Expr, len(index.Columns))
+					for i, colName := range index.Columns {
+						cols[i] = tbl.GetColumnByName(colName)
+						nameParts[i] = cols[i].GoFieldName()
+						callArgs[i] = &ast.SelectorExpr{X: testObj2, Sel: ast.NewIdent(cols[i].GoFieldName())}
+					}
+					funcNameSuffix := strings.Join(nameParts, "And")
+
+					if index.IsUnique {
 						indexGets = append(indexGets, []ast.Stmt{
 							// assert.Equal(t, item2, TestDB.GetItemByXYZ(...))
 							&ast.ExprStmt{X: &ast.CallExpr{ // TODO: what if just delete the "ExprStmt" wrapper?
@@ -354,16 +457,32 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 									testObj2,
 									mustCall(&ast.CallExpr{
 										Fun: &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent(
-											"Get" + pkgschema.TypenameFromTablename(tbl.TableName) + "By" + col.GoFieldName(),
+											"Get" + pkgschema.TypenameFromTablename(tbl.TableName) + "By" + funcNameSuffix,
 										)},
-										Args: []ast.Expr{&ast.SelectorExpr{X: testObj2, Sel: ast.NewIdent(col.GoFieldName())}},
+										Args: callArgs,
 									}),
 								},
 							}},
 						}...)
-						// decls = append(decls, modelgenerate.GenerateGetItemByUniqColFunc(table, table.GetColumnByName(index.Columns[0])))
-						hasIndexedGets = true
+					} else {
+						indexGets = append(indexGets, []ast.Stmt{
+							// assert.Contains(t, TestDB.GetItemsByXYZ(...), item2)
+							&ast.ExprStmt{X: &ast.CallExpr{
+								Fun: &ast.SelectorExpr{X: ast.NewIdent("assert"), Sel: ast.NewIdent("Contains")},
+								Args: []ast.Expr{
+									ast.NewIdent("t"),
+									&ast.CallExpr{
+										Fun: &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent(
+											"Get" + inflection.Plural(pkgschema.TypenameFromTablename(tbl.TableName)) + "By" + funcNameSuffix,
+										)},
+										Args: callArgs,
+									},
+									testObj2,
+								},
+							}},
+						}...)
 					}
+					hasIndexedGets = true
 				}
 
 				if hasIndexedGets {
@@ -384,10 +503,7 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					&ast.AssignStmt{
 						Lhs: []ast.Expr{ast.NewIdent("_"), ast.NewIdent("err")},
 						Tok: token.DEFINE,
-						Rhs: []ast.Expr{&ast.CallExpr{
-							Fun:  &ast.SelectorExpr{X: testDB, Sel: ast.NewIdent("Get" + tbl.GoTypeName + "ByID")},
-							Args: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: ast.NewIdent("ID")}},
-						}},
+						Rhs: []ast.Expr{getItemByPKCall(testObj)},
 					},
 
 					// assert.ErrorIs(t, err, db.ErrNotInDB)
@@ -445,8 +561,7 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						Name: ast.NewIdent("."),
 					},
 					&ast.ImportSpec{
-						Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"`},
-						Name: ast.NewIdent("."),
+						Path: &ast.BasicLit{Kind: token.STRING, Value: `"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"`},
 					},
 					&ast.ImportSpec{
 						Path: &ast.BasicLit{Kind: token.STRING, Value: fmt.Sprintf(`"%s/pkg/%s"`, gomodName, packageName)},

pkg/codegen/pkg.go

@@ -7,7 +7,7 @@ import (
 	"os/exec"
 	"text/template"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 )
 
 //go:embed "tpl"
@@ -22,31 +22,31 @@ type PkgOpts struct {
 func InitPkg(opts PkgOpts) {
 	// Run `go mod init`
 	fmt.Printf("Running...  `go mod init %s`\n", opts.ModuleName)
-	PanicIf(exec.Command("go", "mod", "init", opts.ModuleName).Run())
+	must.Do(exec.Command("go", "mod", "init", opts.ModuleName).Run())
 
 	// Run `git init`, if required
 	if exec.Command("git", "status").Run() != nil {
 		// Not in a git repo yet; init one
 		fmt.Println("Running...  `git init`")
-		PanicIf(exec.Command("git", "init").Run())
+		must.Do(exec.Command("git", "init").Run())
 	}
 
 	// Create package structure
-	PanicIf(os.MkdirAll("pkg/db", 0o755))
-	PanicIf(os.MkdirAll("cmd", 0o755))
-	PanicIf(os.MkdirAll("doc", 0o755))
-	PanicIf(os.MkdirAll("sample_data", 0o755))
+	must.Do(os.MkdirAll("pkg/db", 0o755))
+	must.Do(os.MkdirAll("cmd", 0o755))
+	must.Do(os.MkdirAll("doc", 0o755))
+	must.Do(os.MkdirAll("sample_data", 0o755))
 
-	PanicIf(os.WriteFile("pkg/db/schema.sql", Must(tpl.ReadFile("tpl/schema.sql")), 0o664))
-	PanicIf(os.WriteFile("pkg/db/db.go", Must(tpl.ReadFile("tpl/db.go.tpl")), 0o664))
+	must.Do(os.WriteFile("pkg/db/schema.sql", must.Get(tpl.ReadFile("tpl/schema.sql")), 0o664))
+	must.Do(os.WriteFile("pkg/db/db.go", must.Get(tpl.ReadFile("tpl/db.go.tpl")), 0o664))
 
-	dbTest := Must(os.Create("pkg/db/db_test.go"))
-	defer MustClose(dbTest)
-	t := Must(template.ParseFS(tpl, "tpl/db_test.go.tpl"))
-	PanicIf(t.Execute(dbTest, opts))
+	dbTest := must.Get(os.Create("pkg/db/db_test.go"))
+	defer must.Close(dbTest)
+	t := must.Get(template.ParseFS(tpl, "tpl/db_test.go.tpl"))
+	must.Do(t.Execute(dbTest, opts))
 
-	PanicIf(os.WriteFile("sample_data/mount.sh", Must(tpl.ReadFile("tpl/mount.sh")), 0o775))
-	PanicIf(os.WriteFile("sample_data/reset.sh", Must(tpl.ReadFile("tpl/reset.sh")), 0o775))
+	must.Do(os.WriteFile("sample_data/mount.sh", must.Get(tpl.ReadFile("tpl/mount.sh")), 0o775))
+	must.Do(os.WriteFile("sample_data/reset.sh", must.Get(tpl.ReadFile("tpl/reset.sh")), 0o775))
 
 	// TODO:
 	// - create `pkg/db/errors.go`

pkg/codegen/tpl/db_test.go.tpl

@@ -3,7 +3,7 @@ package db_test
 import (
 	"fmt"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 
 	. "{{ .ModuleName }}/pkg/db"
 )
@@ -14,6 +14,6 @@ func init() {
 	TestDB = MakeDB("tmp")
 }
 func MakeDB(dbName string) *DB {
-	db := Must(Create(fmt.Sprintf("file:%s?mode=memory&cache=shared", dbName)))
+	db := must.Get(Create(fmt.Sprintf("file:%s?mode=memory&cache=shared", dbName)))
 	return db
 }

pkg/flowutils/flowutils.go

@@ -1,18 +0,0 @@
-package flowutils
-
-import "io"
-
-func PanicIf(err error) {
-	if err != nil {
-		panic(err)
-	}
-}
-
-func Must[T any](val T, err error) T {
-	PanicIf(err)
-	return val
-}
-
-func MustClose(closer io.Closer) {
-	PanicIf(closer.Close())
-}

pkg/must/must.go

@@ -0,0 +1,27 @@
+package must
+
+import (
+	"fmt"
+	"io"
+)
+
+func Do(err error) {
+	if err != nil {
+		panic(err)
+	}
+}
+
+func Get[T any](val T, err error) T {
+	Do(err)
+	return val
+}
+
+func Be(condition bool, msg string, args ...any) {
+	if !condition {
+		panic(fmt.Errorf(msg, args...)) //nolint:err113 // not a returned error
+	}
+}
+
+func Close(closer io.Closer) {
+	Do(closer.Close())
+}

pkg/schema/column.go

@@ -0,0 +1,61 @@
+package schema
+
+import (
+	"strings"
+
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
+)
+
+// Column represents a single column in a table.
+type Column struct {
+	TableName              string `db:"table_name"`
+	Name                   string `db:"column_name"`
+	Type                   string `db:"column_type"`
+	IsNotNull              bool   `db:"notnull"`
+	HasDefaultValue        bool   `db:"has_default_value"`
+	DefaultValue           string `db:"dflt_value"`
+	IsPrimaryKey           bool   `db:"is_primary_key"`
+	PrimaryKeyRank         uint   `db:"primary_key_rank"`
+	IsForeignKey           bool   `db:"is_foreign_key"`
+	ForeignKeyTargetTable  string `db:"fk_target_table"`
+	ForeignKeyTargetColumn string `db:"fk_target_column"`
+}
+
+// IsNullableForeignKey is a helper function.
+func (c Column) IsNullableForeignKey() bool {
+	return !c.IsNotNull && !c.IsPrimaryKey && c.IsForeignKey
+}
+
+func (c Column) IsNonCodeTableForeignKey() bool {
+	return c.IsForeignKey && strings.HasSuffix(c.Name, "_id")
+}
+
+func (c Column) GoFieldName() string {
+	if c.Name == "rowid" {
+		return "ID"
+	}
+	if c.IsNonCodeTableForeignKey() {
+		return textutils.SnakeToCamel(strings.TrimSuffix(c.Name, "_id")) + "ID"
+	}
+	return textutils.SnakeToCamel(c.Name)
+}
+
+// GoVarName returns the name of a local variable for this column, e.g., when used as a function parameter.
+func (c Column) GoVarName() string {
+	if c.Name == "rowid" {
+		return strings.ToLower(c.TableName)[0:1] + "ID"
+		// TODO: Or should it just be "id"??
+	}
+	// For foreign keys, use first letter of the target type and "ID".  "UserID" => "uID"
+	if c.IsNonCodeTableForeignKey() {
+		return strings.ToLower(c.ForeignKeyTargetTable)[0:1] + "ID"
+	}
+
+	// Otherwise, just use the whole name
+	return c.LongGoVarName()
+}
+
+// LongGoVarName returns a lowercased version of the field name (Pascal => Camel).
+func (c Column) LongGoVarName() string {
+	return textutils.CamelToPascal(c.GoFieldName())
+}

pkg/schema/index.go

@@ -0,0 +1,10 @@
+package schema
+
+type Index struct {
+	Name      string `db:"index_name"`
+	TableName string `db:"table_name"`
+	Columns   []string
+	IsUnique  bool `db:"is_unique"`
+	// TODO: `where ...` for partial indexes
+	// TODO: identify columns that are expressions
+}

pkg/schema/migration_verification_test.go

@@ -9,7 +9,7 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/db"
-	"git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/schema"
 )
 
@@ -57,7 +57,7 @@ func TestVerifyCorrectMigration(t *testing.T) {
 			alter table t1 add column data3 integer;
 		`
 		db2Config := db.Init(&baseSchema, &[]string{migration})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -77,7 +77,7 @@ func TestVerifyCorrectMigration(t *testing.T) {
 		`
 
 		db2Config := db.Init(&baseSchema, &[]string{migration1, migration2})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -93,7 +93,7 @@ func TestIncorrectMigrations(t *testing.T) {
 
 	t.Run("missing migration", func(t *testing.T) {
 		db2Config := db.Init(&baseSchema, &[]string{})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -114,7 +114,7 @@ func TestIncorrectMigrations(t *testing.T) {
 					rowid integer primary key
 				);
 			`})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 
@@ -136,7 +136,7 @@ func TestIncorrectMigrations(t *testing.T) {
 			);
 			alter table t1 add column data3 text;
 		`})
-		db2 := flowutils.Must(db2Config.Create(":memory:"))
+		db2 := must.Get(db2Config.Create(":memory:"))
 		require.NoError(t, db2Config.CheckAndUpdateVersion(db2))
 		db2Schema := schema.SchemaFromDB(db2)
 

pkg/schema/parse.go

@@ -10,7 +10,7 @@ import (
 	"github.com/jmoiron/sqlx"
 	_ "github.com/mattn/go-sqlite3"
 
-	. "git.offline-twitter.com/offline-labs/gas-stack/pkg/flowutils"
+	"git.offline-twitter.com/offline-labs/gas-stack/pkg/must"
 	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
@@ -38,20 +38,20 @@ func SchemaFromDB(db *sqlx.DB) Schema {
 	db.MustExec(create_views)
 
 	var tables []Table
-	PanicIf(db.Select(&tables, `select name, table_type, is_strict, is_without_rowid from tables`))
+	must.Do(db.Select(&tables, `select name, table_type, is_strict, is_without_rowid from tables`))
 	for _, tbl := range tables {
 		tbl.GoTypeName = TypenameFromTablename(tbl.TableName)
 		tbl.TypeIDName = tbl.GoTypeName + "ID"
 		tbl.VarName = strings.ToLower(string(tbl.TableName[0]))
 
-		PanicIf(db.Select(&tbl.Columns, `select * from columns where table_name = ?`, tbl.TableName))
+		must.Do(db.Select(&tbl.Columns, `select * from columns where table_name = ?`, tbl.TableName))
 		ret.Tables[tbl.TableName] = tbl
 	}
 
 	var indexes []Index
-	PanicIf(db.Select(&indexes, `select index_name, table_name, is_unique from indexes`))
+	must.Do(db.Select(&indexes, `select index_name, table_name, is_unique from indexes`))
 	for _, idx := range indexes {
-		PanicIf(db.Select(&idx.Columns, `select column_name from index_columns where index_name = ? order by rank`, idx.Name))
+		must.Do(db.Select(&idx.Columns, `select column_name from index_columns where index_name = ? order by rank`, idx.Name))
 		ret.Indexes[idx.Name] = idx
 	}
 	return ret

pkg/schema/schema.go

@@ -0,0 +1,6 @@
+package schema
+
+type Schema struct {
+	Tables  map[string]Table
+	Indexes map[string]Index
+}

pkg/schema/table.go

@@ -2,65 +2,8 @@ package schema
 
 import (
 	"sort"
-	"strings"
-
-	"git.offline-twitter.com/offline-labs/gas-stack/pkg/textutils"
 )
 
-// Column represents a single column in a table.
-type Column struct {
-	TableName              string `db:"table_name"`
-	Name                   string `db:"column_name"`
-	Type                   string `db:"column_type"`
-	IsNotNull              bool   `db:"notnull"`
-	HasDefaultValue        bool   `db:"has_default_value"`
-	DefaultValue           string `db:"dflt_value"`
-	IsPrimaryKey           bool   `db:"is_primary_key"`
-	PrimaryKeyRank         uint   `db:"primary_key_rank"`
-	IsForeignKey           bool   `db:"is_foreign_key"`
-	ForeignKeyTargetTable  string `db:"fk_target_table"`
-	ForeignKeyTargetColumn string `db:"fk_target_column"`
-}
-
-// IsNullableForeignKey is a helper function.
-func (c Column) IsNullableForeignKey() bool {
-	return !c.IsNotNull && !c.IsPrimaryKey && c.IsForeignKey
-}
-
-func (c Column) IsNonCodeTableForeignKey() bool {
-	return c.IsForeignKey && strings.HasSuffix(c.Name, "_id")
-}
-
-func (c Column) GoFieldName() string {
-	if c.Name == "rowid" {
-		return "ID"
-	}
-	if c.IsNonCodeTableForeignKey() {
-		return textutils.SnakeToCamel(strings.TrimSuffix(c.Name, "_id")) + "ID"
-	}
-	return textutils.SnakeToCamel(c.Name)
-}
-
-// GoVarName returns the name of a local variable for this column, e.g., when used as a function parameter.
-func (c Column) GoVarName() string {
-	if c.Name == "rowid" {
-		return strings.ToLower(c.TableName)[0:1] + "ID"
-		// TODO: Or should it just be "id"??
-	}
-	// For foreign keys, use first letter of the target type and "ID".  "UserID" => "uID"
-	if c.IsNonCodeTableForeignKey() {
-		return strings.ToLower(c.ForeignKeyTargetTable)[0:1] + "ID"
-	}
-
-	// Otherwise, just use the whole name
-	return c.LongGoVarName()
-}
-
-// LongGoVarName returns a lowercased version of the field name (Pascal => Camel).
-func (c Column) LongGoVarName() string {
-	return textutils.CamelToPascal(c.GoFieldName())
-}
-
 // Table is a single SQLite table.
 type Table struct {
 	TableName string `db:"name"`
@@ -118,17 +61,3 @@ func (t Table) HasAutoTimestamps() (hasCreatedAt bool, hasUpdatedAt bool) {
 	}
 	return
 }
-
-type Index struct {
-	Name      string `db:"index_name"`
-	TableName string `db:"table_name"`
-	Columns   []string
-	IsUnique  bool `db:"is_unique"`
-	// TODO: `where ...` for partial indexes
-	// TODO: identify columns that are expressions
-}
-
-type Schema struct {
-	Tables  map[string]Table
-	Indexes map[string]Index
-}