feat: add TOML codec and envc format support

New toml package (pelletier/go-toml/v2) matching yaml/json options and merge flow. envc convert/get/merge accept --from/--to toml; fixture and CLI tests; docs refresh. Co-authored-by: Cursor <cursoragent@cursor.com>
2026-05-03 10:42:21 +01:00
parent 2d7b97f5ae
commit 474cd88739
16 changed files with 307 additions and 16 deletions
@@ -0,0 +1,117 @@
+package toml
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+	"io"
+	"net/http"
+
+	"github.com/eslider/go-config/internal/bytesutil"
+	"github.com/eslider/go-config/internal/keymap"
+	"github.com/eslider/go-config/internal/merge"
+	"github.com/eslider/go-config/internal/source"
+	"github.com/eslider/go-config/internal/structconv"
+	toml2 "github.com/pelletier/go-toml/v2"
+)
+
+// Codec loads TOML from multiple sources.
+type Codec struct {
+	sources    []source.Source
+	normalizer keymap.Normalizer
+	sliceStrat merge.SliceStrategy
+	structOpts structconv.Options
+	mergeOpts  []merge.Option
+	httpClient *http.Client
+	urlHeader  http.Header
+}
+
+// New creates a TOML codec.
+func New(opts ...Option) *Codec {
+	c := &Codec{
+		normalizer: keymap.LowerAlnum,
+		sliceStrat: merge.Replace,
+		structOpts: structconv.Options{
+			TagName:     "mapstructure",
+			WeaklyTyped: true,
+			Trim:        true,
+		},
+	}
+	for _, o := range opts {
+		o(c)
+	}
+	c.mergeOpts = []merge.Option{merge.WithSliceStrategy(c.sliceStrat)}
+	return c
+}
+
+// Map merges all TOML sources into one map.
+func (c *Codec) Map(ctx context.Context) (map[string]any, error) {
+	if len(c.sources) == 0 {
+		return nil, fmt.Errorf("toml: no sources")
+	}
+	acc := make(map[string]any)
+	for _, s := range c.sources {
+		b, err := bytesutil.ReadAll(ctx, s)
+		if err != nil {
+			return nil, fmt.Errorf("toml: read %s: %w", s.String(), err)
+		}
+		var parsed map[string]any
+		if err := toml2.Unmarshal(b, &parsed); err != nil {
+			return nil, fmt.Errorf("toml: parse %s: %w", s.String(), err)
+		}
+		if parsed == nil {
+			parsed = map[string]any{}
+		}
+		merge.DeepMerge(acc, parsed, c.mergeOpts...)
+	}
+	if c.normalizer != nil {
+		keymap.Walk(acc, c.normalizer)
+	}
+	return acc, nil
+}
+
+// Unmarshal decodes using context.Background.
+func (c *Codec) Unmarshal(dst any) error {
+	return c.UnmarshalContext(context.Background(), dst)
+}
+
+// UnmarshalContext decodes merged TOML into dst.
+func (c *Codec) UnmarshalContext(ctx context.Context, dst any) error {
+	m, err := c.Map(ctx)
+	if err != nil {
+		return err
+	}
+	return structconv.Decode(m, dst, c.structOpts)
+}
+
+// Marshal encodes src to TOML bytes (struct or map[string]any).
+func (c *Codec) Marshal(src any) ([]byte, error) {
+	m, err := encodeToMap(src)
+	if err != nil {
+		return nil, fmt.Errorf("toml: encode: %w", err)
+	}
+	var buf bytes.Buffer
+	enc := toml2.NewEncoder(&buf)
+	enc.SetIndentTables(true)
+	if err := enc.Encode(m); err != nil {
+		return nil, fmt.Errorf("toml: marshal: %w", err)
+	}
+	return buf.Bytes(), nil
+}
+
+// WriteTo writes TOML to w.
+func (c *Codec) WriteTo(w io.Writer, src any) (int64, error) {
+	b, err := c.Marshal(src)
+	if err != nil {
+		return 0, err
+	}
+	n, err := w.Write(b)
+	return int64(n), err
+}
+
+func encodeToMap(src any) (map[string]any, error) {
+	if m, ok := src.(map[string]any); ok {
+		return m, nil
+	}
+	return structconv.Encode(src)
+}
@@ -0,0 +1,41 @@
+package toml
+
+import (
+	"context"
+	"testing"
+
+	"github.com/eslider/go-config/internal/testfixtures"
+)
+
+func TestCodec_IdentityTOMLFixture(t *testing.T) {
+	c := New(WithBytes(testfixtures.Load(t, "identity", "service.toml")))
+	m, err := c.Map(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m["service"].(map[string]any)["name"] != "my-service" {
+		t.Fatalf("%#v", m)
+	}
+}
+
+func TestCodec_MarshalRoundTripMap(t *testing.T) {
+	in := map[string]any{
+		"app": map[string]any{
+			"name": "demo",
+			"port": int64(8080),
+		},
+	}
+	c := New()
+	b, err := c.Marshal(in)
+	if err != nil {
+		t.Fatal(err)
+	}
+	c2 := New(WithBytes(b))
+	m, err := c2.Map(context.Background())
+	if err != nil {
+		t.Fatal(err)
+	}
+	if m["app"].(map[string]any)["name"] != "demo" {
+		t.Fatalf("%#v", m)
+	}
+}
@@ -0,0 +1,3 @@
+// Package toml loads and writes TOML configuration using the shared codec pattern
+// (sources, deep merge, key normalization, struct decode via mapstructure).
+package toml
@@ -0,0 +1,87 @@
+package toml
+
+import (
+	"io"
+	"net/http"
+
+	"github.com/eslider/go-config/internal/keymap"
+	"github.com/eslider/go-config/internal/merge"
+	"github.com/eslider/go-config/internal/source"
+	"github.com/go-viper/mapstructure/v2"
+)
+
+// Option configures a Codec.
+type Option func(*Codec)
+
+// WithBytes appends TOML from bytes.
+func WithBytes(b []byte) Option {
+	return func(c *Codec) { c.sources = append(c.sources, source.Bytes{Data: b, Name: "bytes"}) }
+}
+
+// WithReader appends TOML from r.
+func WithReader(r io.Reader) Option {
+	return func(c *Codec) { c.sources = append(c.sources, source.Reader{R: r, Name: "reader"}) }
+}
+
+// WithFile appends a TOML file path.
+func WithFile(path string) Option {
+	return func(c *Codec) { c.sources = append(c.sources, source.File{Path: path}) }
+}
+
+// WithURL appends TOML from an HTTP(S) URL.
+func WithURL(raw string) Option {
+	return func(c *Codec) {
+		var hdr http.Header
+		if c.urlHeader != nil {
+			hdr = c.urlHeader.Clone()
+		}
+		c.sources = append(c.sources, source.URL{Raw: raw, Header: hdr, HTTPClient: c.httpClient})
+	}
+}
+
+// WithHTTPClient sets the client for subsequent WithURL sources.
+func WithHTTPClient(client *http.Client) Option {
+	return func(c *Codec) { c.httpClient = client }
+}
+
+// WithHTTPHeader adds a header for subsequent WithURL sources.
+func WithHTTPHeader(k, v string) Option {
+	return func(c *Codec) {
+		if c.urlHeader == nil {
+			c.urlHeader = make(http.Header)
+		}
+		c.urlHeader.Add(k, v)
+	}
+}
+
+// WithKeyNormalizer sets key normalizer after merge (nil disables).
+func WithKeyNormalizer(n keymap.Normalizer) Option {
+	return func(c *Codec) { c.normalizer = n }
+}
+
+// WithSliceMerge sets slice merge strategy across sources.
+func WithSliceMerge(s merge.SliceStrategy) Option {
+	return func(c *Codec) { c.sliceStrat = s }
+}
+
+// WithTrim toggles string trim on struct decode.
+func WithTrim(enable bool) Option {
+	return func(c *Codec) { c.structOpts.Trim = enable }
+}
+
+// WithWeaklyTyped toggles weak typing for struct decode.
+func WithWeaklyTyped(enable bool) Option {
+	return func(c *Codec) { c.structOpts.WeaklyTyped = enable }
+}
+
+// WithTagName sets mapstructure tag name.
+func WithTagName(name string) Option {
+	return func(c *Codec) { c.structOpts.TagName = name }
+}
+
+// WithDecodeHook appends a decode hook.
+func WithDecodeHook(h mapstructure.DecodeHookFunc) Option {
+	return func(c *Codec) {
+		c.structOpts.ExtraHooks = append(c.structOpts.ExtraHooks, h)
+	}
+}