mcfg: made SourceCLI and SourceEnv be pointers

m/m.go

@@ -28,7 +28,7 @@ func ProcessContext() context.Context {
 	ctx := context.Background()
 
 	// embed confuration source which should be used into the context.
-	ctx = context.WithValue(ctx, cfgSrcKey(0), mcfg.Source(mcfg.SourceCLI{}))
+	ctx = context.WithValue(ctx, cfgSrcKey(0), mcfg.Source(new(mcfg.SourceCLI)))
 
 	// set up log level handling
 	logger := mlog.NewLogger()
@@ -57,8 +57,8 @@ func ServiceContext() context.Context {
 
 	// services expect to use many different configuration sources
 	ctx = context.WithValue(ctx, cfgSrcKey(0), mcfg.Source(mcfg.Sources{
-		mcfg.SourceEnv{},
+		new(mcfg.SourceEnv),
-		mcfg.SourceCLI{},
+		new(mcfg.SourceCLI),
 	}))
 
 	// TODO set up the debug endpoint.

mcfg/cli.go

@@ -53,7 +53,7 @@ const (
 )
 
 // Parse implements the method for the Source interface
-func (cli SourceCLI) Parse(params []Param) ([]ParamValue, error) {
+func (cli *SourceCLI) Parse(params []Param) ([]ParamValue, error) {
 	args := cli.Args
 	if cli.Args == nil {
 		args = os.Args[1:]
@@ -137,7 +137,7 @@ func (cli SourceCLI) Parse(params []Param) ([]ParamValue, error) {
 	return pvs, nil
 }
 
-func (cli SourceCLI) cliParams(params []Param) (map[string]Param, error) {
+func (cli *SourceCLI) cliParams(params []Param) (map[string]Param, error) {
 	m := map[string]Param{}
 	for _, p := range params {
 		key := strings.Join(append(mctx.Path(p.Context), p.Name), cliKeyJoin)
@@ -146,7 +146,7 @@ func (cli SourceCLI) cliParams(params []Param) (map[string]Param, error) {
 	return m, nil
 }
 
-func (cli SourceCLI) printHelp(w io.Writer, pM map[string]Param) {
+func (cli *SourceCLI) printHelp(w io.Writer, pM map[string]Param) {
 	type pEntry struct {
 		arg string
 		Param

mcfg/cli_test.go

@@ -26,7 +26,7 @@ func TestSourceCLIHelp(t *T) {
 	buf := new(bytes.Buffer)
 	pM, err := src.cliParams(collectParams(ctx))
 	require.NoError(t, err)
-	SourceCLI{}.printHelp(buf, pM)
+	new(SourceCLI).printHelp(buf, pM)
 
 	exp := `
 --baz2 (Required)
@@ -49,7 +49,7 @@ func TestSourceCLIHelp(t *T) {
 func TestSourceCLI(t *T) {
 	type state struct {
 		srcCommonState
-		SourceCLI
+		*SourceCLI
 	}
 
 	type params struct {
@@ -61,7 +61,9 @@ func TestSourceCLI(t *T) {
 		Init: func() mchk.State {
 			var s state
 			s.srcCommonState = newSrcCommonState()
-			s.SourceCLI.Args = make([]string, 0, 16)
+			s.SourceCLI = &SourceCLI{
+				Args: make([]string, 0, 16),
+			}
 			return s
 		},
 		Next: func(ss mchk.State) mchk.Action {
@@ -111,9 +113,11 @@ func TestSourceCLITailCallback(t *T) {
 	ctx, _ = WithBool(ctx, "bar", "")
 
 	var tail []string
-	src := SourceCLI{TailCallback: func(gotTail []string) {
+	src := &SourceCLI{
+		TailCallback: func(gotTail []string) {
 			tail = gotTail
-	}}
+		},
+	}
 
 	type testCase struct {
 		args    []string

mcfg/env.go

@@ -32,7 +32,7 @@ type SourceEnv struct {
 	Prefix string
 }
 
-func (env SourceEnv) expectedName(path []string, name string) string {
+func (env *SourceEnv) expectedName(path []string, name string) string {
 	out := strings.Join(append(path, name), "_")
 	if env.Prefix != "" {
 		out = env.Prefix + "_" + out
@@ -43,7 +43,7 @@ func (env SourceEnv) expectedName(path []string, name string) string {
 }
 
 // Parse implements the method for the Source interface
-func (env SourceEnv) Parse(params []Param) ([]ParamValue, error) {
+func (env *SourceEnv) Parse(params []Param) ([]ParamValue, error) {
 	kvs := env.Env
 	if kvs == nil {
 		kvs = os.Environ()

mcfg/env_test.go

@@ -11,7 +11,7 @@ import (
 func TestSourceEnv(t *T) {
 	type state struct {
 		srcCommonState
-		SourceEnv
+		*SourceEnv
 	}
 
 	type params struct {
@@ -22,7 +22,9 @@ func TestSourceEnv(t *T) {
 		Init: func() mchk.State {
 			var s state
 			s.srcCommonState = newSrcCommonState()
-			s.SourceEnv.Env = make([]string, 0, 16)
+			s.SourceEnv = &SourceEnv{
+				Env: make([]string, 0, 16),
+			}
 			return s
 		},
 		Next: func(ss mchk.State) mchk.Action {

mcfg/mcfg_test.go

@@ -17,7 +17,7 @@ func TestPopulate(t *T) {
 		ctxChild, c := WithInt(ctxChild, "c", 0, "")
 		ctx = mctx.WithChild(ctx, ctxChild)
 
-		err := Populate(ctx, SourceCLI{
+		err := Populate(ctx, &SourceCLI{
 			Args: []string{"--a=1", "--foo-b=2"},
 		})
 		assert.NoError(t, err)
@@ -34,12 +34,12 @@ func TestPopulate(t *T) {
 		ctxChild, c := WithRequiredInt(ctxChild, "c", "")
 		ctx = mctx.WithChild(ctx, ctxChild)
 
-		err := Populate(ctx, SourceCLI{
+		err := Populate(ctx, &SourceCLI{
 			Args: []string{"--a=1", "--foo-b=2"},
 		})
 		assert.Error(t, err)
 
-		err = Populate(ctx, SourceCLI{
+		err = Populate(ctx, &SourceCLI{
 			Args: []string{"--a=1", "--foo-b=2", "--foo-c=3"},
 		})
 		assert.NoError(t, err)

mcfg/source_test.go

@@ -160,8 +160,8 @@ func TestSources(t *T) {
 	ctx, c := WithRequiredInt(ctx, "c", "")
 
 	err := Populate(ctx, Sources{
-		SourceCLI{Args: []string{"--a=1", "--b=666"}},
+		&SourceCLI{Args: []string{"--a=1", "--b=666"}},
-		SourceEnv{Env: []string{"B=2", "C=3"}},
+		&SourceEnv{Env: []string{"B=2", "C=3"}},
 	})
 	massert.Require(t,
 		massert.Nil(err),

mtest/mtest.go

@@ -50,7 +50,7 @@ func Run(ctx context.Context, t *testing.T, body func()) {
 		env = append(env, tup[0]+"="+tup[1])
 	}
 
-	if err := mcfg.Populate(ctx, mcfg.SourceEnv{Env: env}); err != nil {
+	if err := mcfg.Populate(ctx, &mcfg.SourceEnv{Env: env}); err != nil {
 		t.Fatal(err)
 	} else if err := mrun.Start(ctx); err != nil {
 		t.Fatal(err)