fix: correctly populate numeric $value (#11)

* fix: correctly populate numeric $value

* fix: code review

Author: bennypowers

parser/json.go

@@ -13,6 +13,7 @@ import (
 	"math"
 	"slices"
 	"sort"
+	"strconv"
 	"strings"
 
 	"bennypowers.dev/asimonim/fs"
@@ -248,6 +249,13 @@ func (p *JSONParser) createToken(key, path string, valueMap map[string]any, json
 			rawValue = value
 		} else {
 			rawValue = dollarValue
+			// Populate Value for numeric primitives so downstream consumers
+			// (e.g. fallback comparison) have a string representation.
+			if v, ok := dollarValue.(float64); ok {
+				value = strconv.FormatFloat(v, 'f', -1, 64)
+			} else if v, ok := dollarValue.(int); ok {
+				value = strconv.FormatInt(int64(v), 10)
+			}
 		}
 	} else if dollarRef != nil && opts.SchemaVersion != schema.Draft {
 		if strVal, ok := dollarRef.(string); ok {

parser/json_test.go

@@ -193,6 +193,52 @@ func TestJSONParser_AutoDetectSchema(t *testing.T) {
 	})
 }
 
+func TestJSONParser_NumericValues(t *testing.T) {
+	mfs := testutil.NewFixtureFS(t, "fixtures/draft/numeric-values", "/test")
+
+	p := parser.NewJSONParser()
+	tokens, err := p.ParseFile(mfs, "/test/tokens.json", parser.Options{
+		SchemaVersion: schema.Draft,
+	})
+
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	if len(tokens) != 4 {
+		t.Errorf("expected 4 tokens, got %d", len(tokens))
+	}
+
+	// Build lookup by name
+	tokenByName := make(map[string]string)
+	for _, tok := range tokens {
+		tokenByName[tok.Name] = tok.Value
+	}
+
+	// Numeric $value fields must populate Token.Value as a string
+	tests := []struct {
+		name     string
+		expected string
+	}{
+		{"font-weight-regular", "400"},
+		{"font-weight-medium", "500"},
+		{"font-weight-bold", "700"},
+		{"opacity-half", "0.5"},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			val, ok := tokenByName[tt.name]
+			if !ok {
+				t.Fatalf("token %s not found", tt.name)
+			}
+			if val != tt.expected {
+				t.Errorf("Token.Value = %q, want %q", val, tt.expected)
+			}
+		})
+	}
+}
+
 func TestJSONParser_SkipPositions(t *testing.T) {
 	mfs := testutil.NewFixtureFS(t, "fixtures/draft/simple", "/test")
 	data, err := mfs.ReadFile("/test/tokens.json")

testdata/fixtures/draft/numeric-values/tokens.json

@@ -0,0 +1,26 @@
+{
+  "font": {
+    "$type": "fontWeight",
+    "weight": {
+      "regular": {
+        "$value": 400,
+        "$description": "Regular font weight"
+      },
+      "medium": {
+        "$value": 500,
+        "$description": "Medium font weight"
+      },
+      "bold": {
+        "$value": 700,
+        "$description": "Bold font weight"
+      }
+    }
+  },
+  "opacity": {
+    "$type": "number",
+    "half": {
+      "$value": 0.5,
+      "$description": "Half opacity"
+    }
+  }
+}