feat: add module and decimal wire helpers

internal/wire/wire.go

@@ -0,0 +1,69 @@
+package wire
+
+import (
+	"encoding/json"
+	"fmt"
+
+	decimal "github.com/alpacahq/alpacadecimal"
+)
+
+// Unwrap returns the inner JSON of an optional {"data": ...} envelope.
+func Unwrap(raw json.RawMessage) json.RawMessage {
+	if len(raw) == 0 {
+		return raw
+	}
+	var wrap struct {
+		Data json.RawMessage `json:"data"`
+	}
+	if json.Unmarshal(raw, &wrap) == nil && len(wrap.Data) > 0 {
+		return wrap.Data
+	}
+	return raw
+}
+
+// Dec parses a required money/size/price value.
+func Dec(v any) (decimal.Decimal, error) {
+	switch x := v.(type) {
+	case nil:
+		return decimal.Zero, nil
+	case float64:
+		return decimal.NewFromFloat(x), nil
+	case json.Number:
+		d, err := decimal.NewFromString(string(x))
+		if err != nil {
+			return decimal.Zero, fmt.Errorf("parse decimal: %v", v)
+		}
+		return d, nil
+	case string:
+		if x == "" {
+			return decimal.Zero, nil
+		}
+		d, err := decimal.NewFromString(x)
+		if err != nil {
+			return decimal.Zero, fmt.Errorf("parse decimal: %v", v)
+		}
+		return d, nil
+	default:
+		return decimal.Zero, fmt.Errorf("parse decimal: %v", v)
+	}
+}
+
+// DecOpt parses an optional money/size/price value.
+func DecOpt(v any) (*decimal.Decimal, error) {
+	if v == nil {
+		return nil, nil
+	}
+	if s, ok := v.(string); ok && s == "" {
+		return nil, nil
+	}
+	d, err := Dec(v)
+	if err != nil {
+		return nil, err
+	}
+	return &d, nil
+}
+
+// Encode is Decimal.String for Robinhood string wire fields.
+func Encode(d decimal.Decimal) string {
+	return d.String()
+}

internal/wire/wire_test.go

@@ -0,0 +1,85 @@
+package wire_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	decimal "github.com/alpacahq/alpacadecimal"
+	"s1d3sw1ped/robinhood-agentic-mcp/internal/wire"
+)
+
+func TestUnwrap_dataEnvelope(t *testing.T) {
+	t.Parallel()
+	in := json.RawMessage(`{"data":{"cash":"1000"}}`)
+	got := wire.Unwrap(in)
+	if string(got) != `{"cash":"1000"}` {
+		t.Fatalf("got %s", got)
+	}
+}
+
+func TestDec_table(t *testing.T) {
+	t.Parallel()
+	zero := decimal.Zero
+	tests := []struct {
+		name    string
+		in      any
+		want    decimal.Decimal
+		wantErr bool
+	}{
+		{"number", float64(99.6), decimal.RequireFromString("99.6"), false},
+		{"string", "99.60", decimal.RequireFromString("99.60"), false},
+		{"zeroNum", float64(0), zero, false},
+		{"zeroStr", "0", zero, false},
+		{"emptyStr", "", zero, false},
+		{"nil", nil, zero, false},
+		{"bad", "n/a", zero, true},
+		{"obj", map[string]any{"x": 1}, zero, true},
+		{"bool", true, zero, true},
+	}
+	for _, tc := range tests {
+		t.Run(tc.name, func(t *testing.T) {
+			t.Parallel()
+			got, err := wire.Dec(tc.in)
+			if tc.wantErr {
+				if err == nil {
+					t.Fatalf("want error")
+				}
+				return
+			}
+			if err != nil {
+				t.Fatal(err)
+			}
+			if !got.Equal(tc.want) {
+				t.Fatalf("got %s want %s", got, tc.want)
+			}
+		})
+	}
+}
+
+func TestDecOpt_nullIsNil(t *testing.T) {
+	t.Parallel()
+	got, err := wire.DecOpt(nil)
+	if err != nil || got != nil {
+		t.Fatalf("got %v err %v", got, err)
+	}
+	got, err = wire.DecOpt("")
+	if err != nil || got != nil {
+		t.Fatalf("empty string: %v %v", got, err)
+	}
+	got, err = wire.DecOpt("0")
+	if err != nil || got == nil || !got.IsZero() {
+		t.Fatalf("zero: %v %v", got, err)
+	}
+	_, err = wire.DecOpt("n/a")
+	if err == nil {
+		t.Fatal("unparseable must error")
+	}
+}
+
+func TestEncode(t *testing.T) {
+	t.Parallel()
+	d := decimal.RequireFromString("99.6")
+	if wire.Encode(d) != d.String() {
+		t.Fatalf("%q", wire.Encode(d))
+	}
+}