Add GQL and tests

golden_test.go

@@ -48,6 +48,10 @@ var goldenSQL = []Golden{
 	{"prime with SQL", primeSqlIn, primeSqlOut},
 }
 
+var goldenGQL = []Golden{
+	{"prime with GQL", primeGqlIn, primeGqlOut},
+}
+
 var goldenJSONAndSQL = []Golden{
 	{"prime with JSONAndSQL", primeJsonAndSqlIn, primeJsonAndSqlOut},
 }
@@ -887,6 +891,113 @@ func (i *Prime) Scan(value interface{}) error {
 	return nil
 }
 `
+const primeGqlIn = `type Prime int
+const (
+	p2 Prime = 2
+	p3 Prime = 3
+	p5 Prime = 5
+	p7 Prime = 7
+	p77 Prime = 7 // Duplicate; note that p77 doesn't appear below.
+	p11 Prime = 11
+	p13 Prime = 13
+	p17 Prime = 17
+	p19 Prime = 19
+	p23 Prime = 23
+	p29 Prime = 29
+	p37 Prime = 31
+	p41 Prime = 41
+	p43 Prime = 43
+)
+`
+
+const primeGqlOut = `
+const _PrimeName = "p2p3p5p7p11p13p17p19p23p29p37p41p43"
+
+var _PrimeMap = map[Prime]string{
+	2:  _PrimeName[0:2],
+	3:  _PrimeName[2:4],
+	5:  _PrimeName[4:6],
+	7:  _PrimeName[6:8],
+	11: _PrimeName[8:11],
+	13: _PrimeName[11:14],
+	17: _PrimeName[14:17],
+	19: _PrimeName[17:20],
+	23: _PrimeName[20:23],
+	29: _PrimeName[23:26],
+	31: _PrimeName[26:29],
+	41: _PrimeName[29:32],
+	43: _PrimeName[32:35],
+}
+
+func (i Prime) String() string {
+	if str, ok := _PrimeMap[i]; ok {
+		return str
+	}
+	return fmt.Sprintf("Prime(%d)", i)
+}
+
+var _PrimeValues = []Prime{2, 3, 5, 7, 11, 13, 17, 19, 23, 29, 31, 41, 43}
+
+var _PrimeNameToValueMap = map[string]Prime{
+	_PrimeName[0:2]:   2,
+	_PrimeName[2:4]:   3,
+	_PrimeName[4:6]:   5,
+	_PrimeName[6:8]:   7,
+	_PrimeName[8:11]:  11,
+	_PrimeName[11:14]: 13,
+	_PrimeName[14:17]: 17,
+	_PrimeName[17:20]: 19,
+	_PrimeName[20:23]: 23,
+	_PrimeName[23:26]: 29,
+	_PrimeName[26:29]: 31,
+	_PrimeName[29:32]: 41,
+	_PrimeName[32:35]: 43,
+}
+
+// PrimeString retrieves an enum value from the enum constants string name.
+// Throws an error if the param is not part of the enum.
+func PrimeString(s string) (Prime, error) {
+	if val, ok := _PrimeNameToValueMap[s]; ok {
+		return val, nil
+	}
+	return 0, fmt.Errorf("%s does not belong to Prime values", s)
+}
+
+// PrimeValues returns all values of the enum
+func PrimeValues() []Prime {
+	return _PrimeValues
+}
+
+// IsAPrime returns "true" if the value is listed in the enum definition. "false" otherwise
+func (i Prime) IsAPrime() bool {
+	_, ok := _PrimeMap[i]
+	return ok
+}
+
+func (i *Prime) UnmarshalGQL(v interface{}) error {
+	str, ok := v.(string)
+	if !ok {
+		bytes, ok := v.([]byte)
+		if !ok {
+			return fmt.Errorf("value is not a byte slice")
+		}
+
+		str = string(bytes[:])
+	}
+
+	val, err := PrimeString(str)
+	if err != nil {
+		return err
+	}
+
+	*i = val
+	return nil
+}
+
+func (i Prime) MarshalGQL(w io.Writer) {
+	_, _ = w.Write([]byte(strconv.Quote(f.String())))
+}
+`
 
 const primeJsonAndSqlIn = `type Prime int
 const (
@@ -1115,29 +1226,32 @@ func (i Prime) IsAPrime() bool {
 
 func TestGolden(t *testing.T) {
 	for _, test := range golden {
-		runGoldenTest(t, test, false, false, false, false, "")
+		runGoldenTest(t, test, false, false, false, false, false, "")
 	}
 	for _, test := range goldenJSON {
-		runGoldenTest(t, test, true, false, false, false, "")
+		runGoldenTest(t, test, true, false, false, false, false, "")
 	}
 	for _, test := range goldenText {
-		runGoldenTest(t, test, false, false, false, true, "")
+		runGoldenTest(t, test, false, false, false, false, true, "")
 	}
 	for _, test := range goldenYAML {
-		runGoldenTest(t, test, false, true, false, false, "")
+		runGoldenTest(t, test, false, true, false, false, false, "")
 	}
 	for _, test := range goldenSQL {
-		runGoldenTest(t, test, false, false, true, false, "")
+		runGoldenTest(t, test, false, false, true, false, false, "")
+	}
+	for _, test := range goldenGQL {
+		runGoldenTest(t, test, false, false, false, true, false, "")
 	}
 	for _, test := range goldenJSONAndSQL {
-		runGoldenTest(t, test, true, false, true, false, "")
+		runGoldenTest(t, test, true, false, true, false, false, "")
 	}
 	for _, test := range goldenPrefix {
-		runGoldenTest(t, test, false, false, false, false, "Day")
+		runGoldenTest(t, test, false, false, false, false, false, "Day")
 	}
 }
 
-func runGoldenTest(t *testing.T, test Golden, generateJSON, generateYAML, generateSQL, generateText bool, prefix string) {
+func runGoldenTest(t *testing.T, test Golden, generateJSON, generateYAML, generateSQL, generateGQL, generateText bool, prefix string) {
 	var g Generator
 	input := "package test\n" + test.input
 	file := test.name + ".go"
@@ -1164,7 +1278,7 @@ func runGoldenTest(t *testing.T, test Golden, generateJSON, generateYAML, genera
 	if len(tokens) != 3 {
 		t.Fatalf("%s: need type declaration on first line", test.name)
 	}
-	g.generate(tokens[1], generateJSON, generateYAML, generateSQL, generateText, "noop", prefix, false)
+	g.generate(tokens[1], generateJSON, generateYAML, generateSQL, generateGQL, generateText, "noop", prefix, false)
 	got := string(g.format())
 	if got != test.output {
 		t.Errorf("%s: got\n====\n%s====\nexpected\n====%s", test.name, got, test.output)

gql.go

@@ -0,0 +1,36 @@
+package main
+
+// Arguments to format are:
+//	[1]: type name
+const unmarshalGqlMethod = `func (i *%[1]s) UnmarshalGQL(v interface{}) error {
+	str, ok := v.(string)
+	if !ok {
+		bytes, ok := v.([]byte)
+		if !ok {
+			return fmt.Errorf("value is not a byte slice")
+		}
+
+		str = string(bytes[:])
+	}
+
+	val, err := %[1]sString(str)
+	if err != nil {
+		return err
+	}
+
+	*i = val
+	return nil
+}
+`
+
+const marshalGqlMethod = `func (i %[1]s) MarshalGQL(w io.Writer) {
+	_, _ = w.Write([]byte(strconv.Quote(i.String())))
+}
+`
+
+func (g *Generator) addGqlMethods(typeName string) {
+	g.Printf("\n")
+	g.Printf(unmarshalGqlMethod, typeName)
+	g.Printf("\n\n")
+	g.Printf(marshalGqlMethod, typeName)
+}

stringer.go

@@ -20,14 +20,15 @@ import (
 	"go/importer"
 	"go/token"
 	"go/types"
-	"golang.org/x/tools/go/packages"
 	"io/ioutil"
 	"log"
 	"os"
 	"path/filepath"
 	"sort"
 	"strings"
 
+	"golang.org/x/tools/go/packages"
+
 	"github.com/pascaldekloe/name"
 )
 
@@ -44,6 +45,7 @@ func (af *arrayFlags) Set(value string) error {
 
 var (
 	typeNames       = flag.String("type", "", "comma-separated list of type names; must be set")
+	gql             = flag.Bool("gql", false, "if true, the MarshalGQL and UnmarshalGQL interface of GQLGen will be implemented.")
 	sql             = flag.Bool("sql", false, "if true, the Scanner and Valuer interface will be implemented.")
 	json            = flag.Bool("json", false, "if true, json marshaling methods will be generated. Default: false")
 	yaml            = flag.Bool("yaml", false, "if true, yaml marshaling methods will be generated. Default: false")
@@ -117,11 +119,15 @@ func main() {
 	if *json {
 		g.Printf("\t\"encoding/json\"\n")
 	}
+	if *gql {
+		g.Printf("\t\"io\"\n")
+		g.Printf("\t\"strconv\"\n")
+	}
 	g.Printf(")\n")
 
 	// Run generate for each type.
 	for _, typeName := range types {
-		g.generate(typeName, *json, *yaml, *sql, *text, *transformMethod, *trimPrefix, *lineComment)
+		g.generate(typeName, *json, *yaml, *sql, *gql, *text, *transformMethod, *trimPrefix, *lineComment)
 	}
 
 	// Format the output.
@@ -341,7 +347,7 @@ func (g *Generator) replaceValuesWithLineComment(values []Value) {
 }
 
 // generate produces the String method for the named type.
-func (g *Generator) generate(typeName string, includeJSON, includeYAML, includeSQL, includeText bool, transformMethod string, trimPrefix string, lineComment bool) {
+func (g *Generator) generate(typeName string, includeJSON, includeYAML, includeSQL, includeGQL, includeText bool, transformMethod string, trimPrefix string, lineComment bool) {
 	values := make([]Value, 0, 100)
 	for _, file := range g.pkg.files {
 		// Set the state for this run of the walker.
@@ -401,6 +407,9 @@ func (g *Generator) generate(typeName string, includeJSON, includeYAML, includeS
 	if includeSQL {
 		g.addValueAndScanMethod(typeName)
 	}
+	if includeGQL {
+		g.addGqlMethods(typeName)
+	}
 }
 
 // splitIntoRuns breaks the values into runs of contiguous sequences.