Merge pull request #1281 from AkihiroSuda/dev

Make sure `limactl list --json` to print line-delimited JSON

Author: AkihiroSuda

pkg/store/instance.go

@@ -2,7 +2,6 @@ package store
 
 import (
 	"context"
-	"encoding/json"
 	"errors"
 	"fmt"
 	"io"
@@ -18,11 +17,11 @@ import (
 	"time"
 
 	"github.com/docker/go-units"
-	"github.com/goccy/go-yaml"
 	hostagentclient "github.com/lima-vm/lima/pkg/hostagent/api/client"
 	"github.com/lima-vm/lima/pkg/limayaml"
 	"github.com/lima-vm/lima/pkg/store/dirnames"
 	"github.com/lima-vm/lima/pkg/store/filenames"
+	"github.com/lima-vm/lima/pkg/textutil"
 )
 
 type Status = string
@@ -238,17 +237,9 @@ func AddGlobalFields(inst *Instance) (FormatData, error) {
 func PrintInstances(w io.Writer, instances []*Instance, format string) error {
 	switch format {
 	case "json":
-		b, err := json.Marshal(instances)
-		if err != nil {
-			return err
-		}
-		fmt.Fprintln(w, string(b))
+		format = "{{json .}}"
 	case "yaml":
-		b, err := yaml.Marshal(instances)
-		if err != nil {
-			return err
-		}
-		fmt.Fprintln(w, string(b))
+		format = "{{yaml .}}"
 	case "table":
 		w := tabwriter.NewWriter(w, 4, 8, 4, ' ', 0)
 		fmt.Fprintln(w, "NAME\tSTATUS\tSSH\tVMTYPE\tARCH\tCPUS\tMEMORY\tDISK\tDIR")
@@ -278,18 +269,18 @@ func PrintInstances(w io.Writer, instances []*Instance, format string) error {
 		}
 		return w.Flush()
 	default:
-		tmpl, err := template.New("format").Parse(format)
+		// NOP
+	}
+	tmpl, err := template.New("format").Funcs(textutil.TemplateFuncMap).Parse(format)
+	if err != nil {
+		return fmt.Errorf("invalid go template: %w", err)
+	}
+	for _, instance := range instances {
+		err = tmpl.Execute(w, instance)
 		if err != nil {
-			return fmt.Errorf("invalid go template: %w", err)
-		}
-		for _, instance := range instances {
-			err = tmpl.Execute(w, instance)
-			if err != nil {
-				return err
-			}
-			fmt.Fprintln(w)
+			return err
 		}
-		return nil
+		fmt.Fprintln(w)
 	}
 	return nil
 }

pkg/textutil/textutil.go

@@ -2,7 +2,12 @@ package textutil
 
 import (
 	"bytes"
+	"encoding/json"
+	"fmt"
+	"strings"
 	"text/template"
+
+	"github.com/goccy/go-yaml"
 )
 
 // ExecuteTemplate executes a text/template template.
@@ -17,3 +22,24 @@ func ExecuteTemplate(tmpl string, args interface{}) ([]byte, error) {
 	}
 	return b.Bytes(), nil
 }
+
+// TemplateFuncMap is a text/template FuncMap.
+var TemplateFuncMap = template.FuncMap{
+	"json": func(v interface{}) string {
+		var b bytes.Buffer
+		enc := json.NewEncoder(&b)
+		enc.SetEscapeHTML(false)
+		if err := enc.Encode(v); err != nil {
+			panic(fmt.Errorf("failed to marshal as JSON: %+v: %w", v, err))
+		}
+		return strings.TrimSuffix(b.String(), "\n")
+	},
+	"yaml": func(v interface{}) string {
+		var b bytes.Buffer
+		enc := yaml.NewEncoder(&b)
+		if err := enc.Encode(v); err != nil {
+			panic(fmt.Errorf("failed to marshal as YAML: %+v: %w", v, err))
+		}
+		return "---\n" + strings.TrimSuffix(b.String(), "\n")
+	},
+}

pkg/textutil/textutil_test.go

@@ -0,0 +1,32 @@
+package textutil
+
+import (
+	"bytes"
+	"testing"
+	"text/template"
+
+	"gotest.tools/v3/assert"
+)
+
+func TestTemplateFuncs(t *testing.T) {
+	type X struct {
+		Foo int    `json:"foo" yaml:"foo"`
+		Bar string `json:"bar" yaml:"bar"`
+	}
+	x := X{Foo: 42, Bar: "hello"}
+
+	testCases := map[string]string{
+		"{{json .}}": `{"foo":42,"bar":"hello"}`,
+		"{{yaml .}}": `---
+foo: 42
+bar: hello`,
+	}
+
+	for format, expected := range testCases {
+		tmpl, err := template.New("format").Funcs(TemplateFuncMap).Parse(format)
+		assert.NilError(t, err)
+		var b bytes.Buffer
+		assert.NilError(t, tmpl.Execute(&b, x))
+		assert.Equal(t, expected, b.String())
+	}
+}