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Add optional "Validate() error" method #82

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4 changes: 3 additions & 1 deletion README.md
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Expand Up @@ -3,7 +3,7 @@

Enumer is a tool to generate Go code that adds useful methods to Go enums (constants with a specific type).
It started as a fork of [Rob Pike’s Stringer tool](https://godoc.org/golang.org/x/tools/cmd/stringer)
maintained by [Álvaro López Espinosa](https://github.com/alvaroloes/enumer).
maintained by [Álvaro López Espinosa](https://github.com/alvaroloes/enumer).
This was again forked here as (https://github.com/dmarkham/enumer) picking up where Álvaro left off.


Expand Down Expand Up @@ -40,6 +40,8 @@ Flags:
comma-separated list of type names; must be set
-values
if true, alternative string values method will be generated. Default: false
-validate
if true, a `Validate() error` method will be generated. Default: false
-yaml
if true, yaml marshaling methods will be generated. Default: false
```
Expand Down
27 changes: 26 additions & 1 deletion enumer.go
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Original file line number Diff line number Diff line change
Expand Up @@ -3,6 +3,7 @@ package main
import "fmt"

// Arguments to format are:
//
// [1]: type name
const stringNameToValueMethod = `// %[1]sString retrieves an enum value from the enum constants string name.
// Throws an error if the param is not part of the enum.
Expand All @@ -19,6 +20,7 @@ func %[1]sString(s string) (%[1]s, error) {
`

// Arguments to format are:
//
// [1]: type name
const stringValuesMethod = `// %[1]sValues returns all values of the enum
func %[1]sValues() []%[1]s {
Expand All @@ -27,6 +29,7 @@ func %[1]sValues() []%[1]s {
`

// Arguments to format are:
//
// [1]: type name
const stringsMethod = `// %[1]sStrings returns a slice of all String values of the enum
func %[1]sStrings() []string {
Expand All @@ -37,6 +40,7 @@ func %[1]sStrings() []string {
`

// Arguments to format are:
//
// [1]: type name
const stringBelongsMethodLoop = `// IsA%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
func (i %[1]s) IsA%[1]s() bool {
Expand All @@ -50,15 +54,29 @@ func (i %[1]s) IsA%[1]s() bool {
`

// Arguments to format are:
//
// [1]: type name
const stringBelongsMethodSet = `// IsA%[1]s returns "true" if the value is listed in the enum definition. "false" otherwise
func (i %[1]s) IsA%[1]s() bool {
_, ok := _%[1]sMap[i]
_, ok := _%[1]sMap[i]
return ok
}
`

// Arguments to format are:
//
// [1]: type name
const validateMethod = `// Validate returns an error if the value is not listed in the enum definition.
func (i %[1]s) Validate() error {
if !i.IsA%[1]s() {
return fmt.Errorf("%%d is not a valid value for %[1]s values", i)
}
return nil
}
`

// Arguments to format are:
//
// [1]: type name
const altStringValuesMethod = `func (%[1]s) Values() []string {
return %[1]sStrings()
Expand Down Expand Up @@ -144,6 +162,7 @@ func (g *Generator) printNamesSlice(runs [][]Value, typeName string, runsThresho
}

// Arguments to format are:
//
// [1]: type name
const jsonMethods = `
// MarshalJSON implements the json.Marshaler interface for %[1]s
Expand All @@ -169,6 +188,7 @@ func (g *Generator) buildJSONMethods(runs [][]Value, typeName string, runsThresh
}

// Arguments to format are:
//
// [1]: type name
const textMethods = `
// MarshalText implements the encoding.TextMarshaler interface for %[1]s
Expand All @@ -189,6 +209,7 @@ func (g *Generator) buildTextMethods(runs [][]Value, typeName string, runsThresh
}

// Arguments to format are:
//
// [1]: type name
const yamlMethods = `
// MarshalYAML implements a YAML Marshaler for %[1]s
Expand All @@ -212,3 +233,7 @@ func (i *%[1]s) UnmarshalYAML(unmarshal func(interface{}) error) error {
func (g *Generator) buildYAMLMethods(runs [][]Value, typeName string, runsThreshold int) {
g.Printf(yamlMethods, typeName)
}

func (g *Generator) buildValidateMethod(typeName string) {
g.Printf(validateMethod, typeName)
}
107 changes: 52 additions & 55 deletions golden_test.go
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Original file line number Diff line number Diff line change
Expand Up @@ -10,6 +10,7 @@
package main

import (
"fmt"
"io/ioutil"
"os"
"path/filepath"
Expand Down Expand Up @@ -76,6 +77,10 @@ var goldenLinecomment = []Golden{
{"dayWithLinecomment", linecommentIn},
}

var goldenValidateMethod = []Golden{
{name: "validate", input: dayIn},
}

// Each example starts with "type XXX [u]int", with a single space separating them.

// Simple test: enumeration of type int starting at 0.
Expand Down Expand Up @@ -315,95 +320,87 @@ const (

func TestGolden(t *testing.T) {
for _, test := range golden {
runGoldenTest(t, test, false, false, false, false, false, false, true, "", "")
runGoldenTest(t, test, false, false, false, false, false, false, true, false, "", "")
}
for _, test := range goldenJSON {
runGoldenTest(t, test, true, false, false, false, false, false, false, "", "")
runGoldenTest(t, test, true, false, false, false, false, false, false, false, "", "")
}
for _, test := range goldenText {
runGoldenTest(t, test, false, false, false, true, false, false, false, "", "")
runGoldenTest(t, test, false, false, false, true, false, false, false, false, "", "")
}
for _, test := range goldenYAML {
runGoldenTest(t, test, false, true, false, false, false, false, false, "", "")
runGoldenTest(t, test, false, true, false, false, false, false, false, false, "", "")
}
for _, test := range goldenSQL {
runGoldenTest(t, test, false, false, true, false, false, false, false, "", "")
runGoldenTest(t, test, false, false, true, false, false, false, false, false, "", "")
}
for _, test := range goldenJSONAndSQL {
runGoldenTest(t, test, true, false, true, false, false, false, false, "", "")
runGoldenTest(t, test, true, false, true, false, false, false, false, false, "", "")
}
for _, test := range goldenGQLGen {
runGoldenTest(t, test, false, false, false, false, false, true, false, "", "")
runGoldenTest(t, test, false, false, false, false, false, true, false, false, "", "")
}
for _, test := range goldenTrimPrefix {
runGoldenTest(t, test, false, false, false, false, false, false, false, "Day", "")
runGoldenTest(t, test, false, false, false, false, false, false, false, false, "Day", "")
}
for _, test := range goldenTrimPrefixMultiple {
runGoldenTest(t, test, false, false, false, false, false, false, false, "Day,Night", "")
runGoldenTest(t, test, false, false, false, false, false, false, false, false, "Day,Night", "")
}
for _, test := range goldenWithPrefix {
runGoldenTest(t, test, false, false, false, false, false, false, false, "", "Day")
runGoldenTest(t, test, false, false, false, false, false, false, false, false, "", "Day")
}
for _, test := range goldenTrimAndAddPrefix {
runGoldenTest(t, test, false, false, false, false, false, false, false, "Day", "Night")
runGoldenTest(t, test, false, false, false, false, false, false, false, false, "Day", "Night")
}
for _, test := range goldenLinecomment {
runGoldenTest(t, test, false, false, false, false, true, false, false, "", "")
runGoldenTest(t, test, false, false, false, false, true, false, false, false, "", "")
}
for _, test := range goldenValidateMethod {
runGoldenTest(t, test, false, false, false, false, false, false, false, true, "", "")
}
}

func runGoldenTest(t *testing.T, test Golden,
generateJSON, generateYAML, generateSQL, generateText, linecomment, generateGQLGen, generateValuesMethod bool,
generateJSON, generateYAML, generateSQL, generateText, linecomment, generateGQLGen, generateValuesMethod, generateIsValidMethod bool,
trimPrefix string, prefix string) {
t.Run(test.name, func(t *testing.T) {
var g Generator
file := test.name + ".go"
input := "package test\n" + test.input

var g Generator
file := test.name + ".go"
input := "package test\n" + test.input
dir := t.TempDir()

dir, err := ioutil.TempDir("", "stringer")
if err != nil {
t.Error(err)
}
defer func() {
err = os.RemoveAll(dir)
absFile := filepath.Join(dir, file)
err := ioutil.WriteFile(absFile, []byte(input), 0644)
if err != nil {
t.Error(err)
t.Fatal("writing test input to file:", err)
}
}()

absFile := filepath.Join(dir, file)
err = ioutil.WriteFile(absFile, []byte(input), 0644)
if err != nil {
t.Error(err)
}
g.parsePackage([]string{absFile}, nil)
// Extract the name and type of the constant from the first line.
tokens := strings.SplitN(test.input, " ", 3)
if len(tokens) != 3 {
t.Fatalf("%s: need type declaration on first line", test.name)
}
g.generate(tokens[1], generateJSON, generateYAML, generateSQL, generateText, generateGQLGen, "noop", trimPrefix, prefix, linecomment, generateValuesMethod)
got := string(g.format())
if got != loadGolden(test.name) {
// Use this to help build a golden text when changes are needed
//goldenFile := fmt.Sprintf("./testdata/%v.golden", test.name)
//err = ioutil.WriteFile(goldenFile, []byte(got), 0644)
//if err != nil {
// t.Error(err)
//}
t.Errorf("%s: got\n====\n%s====\nexpected\n====%s", test.name, got, loadGolden(test.name))
}
g.parsePackage([]string{absFile}, nil)
// Extract the name and type of the constant from the first line.
tokens := strings.SplitN(test.input, " ", 3)
if len(tokens) != 3 {
t.Fatalf("%s: need type declaration on first line", test.name)
}
g.generate(tokens[1], generateJSON, generateYAML, generateSQL, generateText, generateGQLGen, "noop", trimPrefix, prefix, linecomment, generateValuesMethod, generateIsValidMethod)
got := string(g.format())
golden := loadGolden(t, test.name)
if got != golden {
// Use this to help build a golden text when changes are needed
// goldenFile := fmt.Sprintf("./testdata/%v.golden", test.name)
// err = ioutil.WriteFile(goldenFile, []byte(got), 0644)
// if err != nil {
// t.Error(err)
// }
t.Errorf("%s: got\n====\n%s====\nexpected\n====%s", test.name, got, golden)
}
})
}

func loadGolden(name string) string {
fh, err := os.Open("testdata/" + name + ".golden")
if err != nil {
return ""
}
defer fh.Close()
b, err := ioutil.ReadAll(fh)
func loadGolden(t *testing.T, name string) string {
t.Helper()
b, err := os.ReadFile(fmt.Sprintf("./testdata/%v.golden", name))
if err != nil {
return ""
t.Fatalf("error while loading golden file %v: %v", name, err)
}
return string(b)

Expand Down
24 changes: 15 additions & 9 deletions stringer.go
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Expand Up @@ -51,6 +51,7 @@ var (
text = flag.Bool("text", false, "if true, text marshaling methods will be generated. Default: false")
gqlgen = flag.Bool("gqlgen", false, "if true, GraphQL marshaling methods for gqlgen will be generated. Default: false")
altValuesFunc = flag.Bool("values", false, "if true, alternative string values method will be generated. Default: false")
validateFunc = flag.Bool("validate", false, "if true, a `Validate() error` method will be generated. Default: false")
output = flag.String("output", "", "output file name; default srcdir/<type>_string.go")
transformMethod = flag.String("transform", "noop", "enum item name transformation method. Default: noop")
trimPrefix = flag.String("trimprefix", "", "transform each item name by removing a prefix. Default: \"\"")
Expand Down Expand Up @@ -135,7 +136,7 @@ func main() {

// Run generate for each type.
for _, typeName := range typs {
g.generate(typeName, *json, *yaml, *sql, *text, *gqlgen, *transformMethod, *trimPrefix, *addPrefix, *linecomment, *altValuesFunc)
g.generate(typeName, *json, *yaml, *sql, *text, *gqlgen, *transformMethod, *trimPrefix, *addPrefix, *linecomment, *altValuesFunc, *validateFunc)
}

// Format the output.
Expand Down Expand Up @@ -415,7 +416,7 @@ func (g *Generator) prefixValueNames(values []Value, prefix string) {
// generate produces the String method for the named type.
func (g *Generator) generate(typeName string,
includeJSON, includeYAML, includeSQL, includeText, includeGQLGen bool,
transformMethod string, trimPrefix string, addPrefix string, lineComment bool, includeValuesMethod bool) {
transformMethod string, trimPrefix string, addPrefix string, lineComment bool, includeValuesMethod bool, includeValidateFunc bool) {
values := make([]Value, 0, 100)
for _, file := range g.pkg.files {
file.lineComment = lineComment
Expand Down Expand Up @@ -465,6 +466,9 @@ func (g *Generator) generate(typeName string,
if includeValuesMethod {
g.buildAltStringValuesMethod(typeName)
}
if includeValidateFunc {
g.buildValidateMethod(typeName)
}

g.buildNoOpOrderChangeDetect(runs, typeName)

Expand Down Expand Up @@ -774,9 +778,10 @@ func (g *Generator) buildOneRun(runs [][]Value, typeName string) {
}

// Arguments to format are:
// [1]: type name
// [2]: size of index element (8 for uint8 etc.)
// [3]: less than zero check (for signed types)
//
// [1]: type name
// [2]: size of index element (8 for uint8 etc.)
// [3]: less than zero check (for signed types)
const stringOneRun = `func (i %[1]s) String() string {
if %[3]si >= %[1]s(len(_%[1]sIndex)-1) {
return fmt.Sprintf("%[1]s(%%d)", i)
Expand All @@ -786,10 +791,11 @@ const stringOneRun = `func (i %[1]s) String() string {
`

// Arguments to format are:
// [1]: type name
// [2]: lowest defined value for type, as a string
// [3]: size of index element (8 for uint8 etc.)
// [4]: less than zero check (for signed types)
//
// [1]: type name
// [2]: lowest defined value for type, as a string
// [3]: size of index element (8 for uint8 etc.)
// [4]: less than zero check (for signed types)
const stringOneRunWithOffset = `func (i %[1]s) String() string {
i -= %[2]s
if %[4]si >= %[1]s(len(_%[1]sIndex)-1) {
Expand Down
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