codegen: make test fixture factory function intelligent about what fields and values it assigns

pkg/codegen/modelgenerate/generate_testfile.go

@@ -4,6 +4,7 @@ import (
 	"fmt"
 	"go/ast"
 	"go/token"
+	"strings"
 
 	"github.com/jinzhu/inflection"
 
@@ -11,6 +12,80 @@ 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 +93,9 @@ 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 +113,15 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 					Results: []ast.Expr{
 						&ast.CompositeLit{
 							Type: ast.NewIdent(tbl.GoTypeName),
-							Elts: []ast.Expr{
+							Elts: func() (ret []ast.Expr) {
-								&ast.KeyValueExpr{
+								for _, c := range updateTestFields {
-									Key: ast.NewIdent("Data"),
+									ret = append(ret, &ast.KeyValueExpr{
-									Value: &ast.CompositeLit{
+										Key:   ast.NewIdent(c.GoFieldName()),
-										Type: &ast.ArrayType{
+										Value: SampleValue(c, 0),
-											Elt: ast.NewIdent("byte"),
+									})
-										},
+								}
-										Elts: []ast.Expr{},
+								return
-									},
+							}(),
-								},
-								&ast.KeyValueExpr{
-									Key: ast.NewIdent("Description"),
-									Value: &ast.BasicLit{
-										Kind:  token.STRING,
-										Value: `""`,
-									},
-								},
-							},
 						},
 					},
 				},
@@ -62,13 +131,8 @@ 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()
-
 	makeDeepEqual := func(obj1 *ast.Ident, obj2 *ast.Ident) *ast.IfStmt {
 		return &ast.IfStmt{
 			Init: &ast.AssignStmt{
@@ -236,23 +300,22 @@ 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"
+					// item.Description = <sample value, offset 1>
-					&ast.AssignStmt{
+					// ...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{
+						Rhs: []ast.Expr{SampleValue(c, 1)},
-							&ast.BasicLit{
+					})
-								Kind:  token.STRING,
+				}
-								Value: fmt.Sprintf("%q", description1),
+				stmts = append(stmts,
-							},
-						},
-					},
-
 					// TestDB.SaveItem(&item), possibly with error check
 					&ast.ExprStmt{X: func() *ast.CallExpr {
 						mainExpr := &ast.CallExpr{
@@ -274,7 +337,7 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 						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
 				if hasCreatedAt {
@@ -305,14 +368,19 @@ func GenerateModelTestAST(tbl pkgschema.Table, schema pkgschema.Schema, gomodNam
 				stmts = append(stmts,
 					BlankLine(),
 					Comment("Update"),
+				)
 
-					// item.Description = "a big item"
+				// item.Description = <sample value, offset 2>
-					&ast.AssignStmt{
+				// ...one assignment per updatable field
-						Lhs: []ast.Expr{&ast.SelectorExpr{X: testObj, Sel: fieldName}},
+				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)},