commit 9545e7752d9fab98f867431cad56ce46235b16dd
Author: jolheiser <john.olheiser@gmail.com>
Date:   Tue Jun 4 09:17:23 2024 -0500

    feat: ffhujson
    
    Signed-off-by: jolheiser <john.olheiser@gmail.com>

diff --git a/LICENSE b/LICENSE
new file mode 100644
index 0000000..b09cd78
--- /dev/null
+++ b/LICENSE
@@ -0,0 +1,201 @@
+Apache License
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diff --git a/ff_map.go b/ff_map.go
new file mode 100644
index 0000000..c4618cf
--- /dev/null
+++ b/ff_map.go
@@ -0,0 +1,64 @@
+// This is taken from https://github.com/peterbourgon/ff/blob/e267c41b1d149b5151fb637d65f53b6e833448fd/internal/traverse_map.go
+package ffhujson
+
+import (
+	"encoding/json"
+	"fmt"
+	"strconv"
+)
+
+// traverseMap recursively walks the given map, calling set for each value. If the
+// value is a slice, set is called for each element of the slice. The keys of
+// nested maps are joined with the given delimiter.
+func traverseMap(m map[string]any, delimiter string, set func(name, value string) error) error {
+	return traverse("", m, delimiter, set)
+}
+
+func traverse(key string, val any, delimiter string, set func(name, value string) error) error {
+	switch v := val.(type) {
+	case string:
+		return set(key, v)
+	case json.Number:
+		return set(key, v.String())
+	case uint64:
+		return set(key, strconv.FormatUint(v, 10))
+	case int:
+		return set(key, strconv.Itoa(v))
+	case int64:
+		return set(key, strconv.FormatInt(v, 10))
+	case float64:
+		return set(key, strconv.FormatFloat(v, 'g', -1, 64))
+	case bool:
+		return set(key, strconv.FormatBool(v))
+	case nil:
+		return set(key, "")
+	case []any:
+		for _, v := range v {
+			if err := traverse(key, v, delimiter, set); err != nil {
+				return err
+			}
+		}
+	case map[string]any:
+		for k, v := range v {
+			if key != "" {
+				k = key + delimiter + k
+			}
+			if err := traverse(k, v, delimiter, set); err != nil {
+				return err
+			}
+		}
+	case map[any]any:
+		for k, v := range v {
+			ks := fmt.Sprint(k)
+			if key != "" {
+				ks = key + delimiter + ks
+			}
+			if err := traverse(ks, v, delimiter, set); err != nil {
+				return err
+			}
+		}
+	default:
+		return fmt.Errorf("couldn't convert %q (type %T) to string", val, val)
+	}
+	return nil
+}
diff --git a/ffhujson.go b/ffhujson.go
new file mode 100644
index 0000000..25b97c3
--- /dev/null
+++ b/ffhujson.go
@@ -0,0 +1,71 @@
+package ffhujson
+
+import (
+	"bytes"
+	"encoding/json"
+	"fmt"
+	"io"
+
+	"github.com/tailscale/hujson"
+)
+
+// Parser is a helper function that uses a default ParseConfig.
+func Parser(r io.Reader, set func(name, value string) error) error {
+	return (&ParseConfig{}).Parse(r, set)
+}
+
+// ParseConfig collects parameters for the  config file parser.
+type ParseConfig struct {
+	// Delimiter is used when concatenating nested node keys into a flag name.
+	// The default delimiter is ".".
+	Delimiter string
+}
+
+// Parse a  document from the provided io.Reader, using the provided set
+// function to set flag values. Flag names are derived from the node names and
+// their key/value pairs.
+func (pc *ParseConfig) Parse(r io.Reader, set func(name, value string) error) error {
+	if pc.Delimiter == "" {
+		pc.Delimiter = "."
+	}
+
+	data, err := io.ReadAll(r)
+	if err != nil {
+		return err
+	}
+
+	data, err = hujson.Standardize(data)
+	if err != nil {
+		return err
+	}
+
+	d := json.NewDecoder(bytes.NewBuffer(data))
+	d.UseNumber() // required for stringifying values
+
+	var m map[string]interface{}
+	if err := d.Decode(&m); err != nil {
+		return ParseError{Inner: err}
+	}
+
+	if err := traverseMap(m, pc.Delimiter, set); err != nil {
+		return ParseError{Inner: err}
+	}
+
+	return nil
+}
+
+// ParseError wraps all errors originating from the Parser.
+type ParseError struct {
+	Inner error
+}
+
+// Error implenents the error interface.
+func (e ParseError) Error() string {
+	return fmt.Sprintf("error parsing  config: %v", e.Inner)
+}
+
+// Unwrap implements the errors.Wrapper interface, allowing errors.Is and
+// errors.As to work with ParseErrors.
+func (e ParseError) Unwrap() error {
+	return e.Inner
+}
diff --git a/ffhujson_test.go b/ffhujson_test.go
new file mode 100644
index 0000000..889e2dd
--- /dev/null
+++ b/ffhujson_test.go
@@ -0,0 +1,56 @@
+package ffhujson_test
+
+import (
+	"io"
+	"testing"
+	"time"
+
+	"github.com/peterbourgon/ff/v3"
+	"github.com/peterbourgon/ff/v3/fftest"
+	"go.jolheiser.com/ffhujson"
+)
+
+func TestJSONParser(t *testing.T) {
+	t.Parallel()
+
+	for _, testcase := range []struct {
+		name string
+		args []string
+		file string
+		want fftest.Vars
+	}{
+		{
+			name: "empty input",
+			args: []string{},
+			file: "testdata/empty.json",
+			want: fftest.Vars{WantParseErrorIs: io.ErrUnexpectedEOF},
+		},
+		{
+			name: "basic KV pairs",
+			args: []string{},
+			file: "testdata/basic.json",
+			want: fftest.Vars{S: "s", I: 10, B: true, D: 5 * time.Second},
+		},
+		{
+			name: "value arrays",
+			args: []string{},
+			file: "testdata/value_arrays.json",
+			want: fftest.Vars{S: "bb", I: 12, B: true, D: 5 * time.Second, X: []string{"a", "B", "👍"}},
+		},
+		{
+			name: "bad JSON file",
+			args: []string{},
+			file: "testdata/bad.json",
+			want: fftest.Vars{WantParseErrorIs: io.ErrUnexpectedEOF},
+		},
+	} {
+		t.Run(testcase.name, func(t *testing.T) {
+			fs, vars := fftest.Pair()
+			vars.ParseError = ff.Parse(fs, testcase.args,
+				ff.WithConfigFile(testcase.file),
+				ff.WithConfigFileParser(ffhujson.Parser),
+			)
+			fftest.Compare(t, &testcase.want, vars)
+		})
+	}
+}
diff --git a/go.mod b/go.mod
new file mode 100644
index 0000000..4af79e2
--- /dev/null
+++ b/go.mod
@@ -0,0 +1,8 @@
+module go.jolheiser.com/ffhujson
+
+go 1.22.3
+
+require (
+	github.com/peterbourgon/ff/v3 v3.4.0
+	github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a
+)
diff --git a/go.sum b/go.sum
new file mode 100644
index 0000000..76e7936
--- /dev/null
+++ b/go.sum
@@ -0,0 +1,6 @@
+github.com/google/go-cmp v0.5.8 h1:e6P7q2lk1O+qJJb4BtCQXlK8vWEO8V1ZeuEdJNOqZyg=
+github.com/google/go-cmp v0.5.8/go.mod h1:17dUlkBOakJ0+DkrSSNjCkIjxS6bF9zb3elmeNGIjoY=
+github.com/peterbourgon/ff/v3 v3.4.0 h1:QBvM/rizZM1cB0p0lGMdmR7HxZeI/ZrBWB4DqLkMUBc=
+github.com/peterbourgon/ff/v3 v3.4.0/go.mod h1:zjJVUhx+twciwfDl0zBcFzl4dW8axCRyXE/eKY9RztQ=
+github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a h1:SJy1Pu0eH1C29XwJucQo73FrleVK6t4kYz4NVhp34Yw=
+github.com/tailscale/hujson v0.0.0-20221223112325-20486734a56a/go.mod h1:DFSS3NAGHthKo1gTlmEcSBiZrRJXi28rLNd/1udP1c8=
diff --git a/testdata/bad.json b/testdata/bad.json
new file mode 100644
index 0000000..98232c6
--- /dev/null
+++ b/testdata/bad.json
@@ -0,0 +1 @@
+{
diff --git a/testdata/basic.json b/testdata/basic.json
new file mode 100644
index 0000000..338c60c
--- /dev/null
+++ b/testdata/basic.json
@@ -0,0 +1,6 @@
+{
+    "s": "s",
+    "i": 10,
+    "b": true,
+    "d": "5s"
+}
diff --git a/testdata/empty.json b/testdata/empty.json
new file mode 100644
index 0000000..e69de29
diff --git a/testdata/value_arrays.json b/testdata/value_arrays.json
new file mode 100644
index 0000000..064ee07
--- /dev/null
+++ b/testdata/value_arrays.json
@@ -0,0 +1,7 @@
+{
+    "s": ["a", "bb"],
+    "i":["10","11","12"],
+    "b": [ false, true ],
+    "d": ["10m", "5s"],
+    "x": ["a" , "B", "👍"]
+}