wit, wit/bindgen: do not emit incompatible feature gates when generating WIT

CHANGELOG.md

@@ -8,6 +8,11 @@ The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.1.0/),
 
 - Removed remaining Go 1.22 support.
 
+### Fixed
+
+- [#306](https://github.com/bytecodealliance/go-modules/issues/306): do not emit incompatible version feature gates when serializing WIT. For example, if a world with version `0.1.0` *includes* a world from another package with a `@since(version = 0.2.0)` feature gate, then strip that feature gate when serializing to WIT if the version is greater than the world’s package version.
+
+
 ## [v0.6.2] — 2025-03-16
 
 ### Fixed

testdata/issues/issue306.wit

@@ -1,12 +1,13 @@
 // https://github.com/bytecodealliance/go-modules/issues/306
-package issues:issue306;
+package issues:issue306@0.1.0;
 
 world w {
-    include issues:dep1/w;
+    include issues:dep1/w@0.2.1;
 }
 
-package issues:dep1 {
+package issues:dep1@0.2.1 {
 	world w {
+		@since(version = 0.2.0)
 		import issues:dep2/gated-interface;
 	}
 }

testdata/issues/issue306.wit.json

@@ -5,7 +5,12 @@
       "imports": {
         "interface-0": {
           "interface": {
-            "id": 0
+            "id": 0,
+            "stability": {
+              "stable": {
+                "since": "0.2.0"
+              }
+            }
           }
         }
       },
@@ -17,7 +22,12 @@
       "imports": {
         "interface-0": {
           "interface": {
-            "id": 0
+            "id": 0,
+            "stability": {
+              "stable": {
+                "since": "0.2.0"
+              }
+            }
           }
         }
       },
@@ -60,14 +70,14 @@
       "worlds": {}
     },
     {
-      "name": "issues:dep1",
+      "name": "issues:dep1@0.2.1",
       "interfaces": {},
       "worlds": {
         "w": 0
       }
     },
     {
-      "name": "issues:issue306",
+      "name": "issues:issue306@0.1.0",
       "docs": {
         "contents": "https://github.com/bytecodealliance/go-modules/issues/306"
       },

testdata/issues/issue306.wit.json.golden.wit

@@ -1,11 +1,12 @@
-package issues:dep1;
+package issues:dep1@0.2.1;
 
 world w {
+	@since(version = 0.2.0)
 	import issues:dep2/gated-interface;
 }
 
 /// https://github.com/bytecodealliance/go-modules/issues/306
-package issues:issue306 {
+package issues:issue306@0.1.0 {
 	world w {
 		import issues:dep2/gated-interface;
 	}

wit/bindgen/generator.go

@@ -29,6 +29,7 @@ import (
 	"go.bytecodealliance.org/internal/wasmtools"
 	"go.bytecodealliance.org/wit"
 	"go.bytecodealliance.org/wit/logging"
+	"go.bytecodealliance.org/wit/ordered"
 )
 
 const (
@@ -166,7 +167,7 @@ func newGenerator(res *wit.Resolve, opts ...Option) (*generator, error) {
 		if g.world.Match(g.opts.world) {
 			break
 		}
-		// otherwise chose the last world
+		// otherwise choose the last world
 	}
 	g.wasmTools, err = wasmtools.New(context.Background())
 	if err != nil {
@@ -2439,10 +2440,25 @@ func synthesizeWorld(r *wit.Resolve, w *wit.World, name string) (*wit.Resolve, *
 	w = w.Clone()
 	w.Name = name
 	w.Docs = wit.Docs{}
+	// stripStability(w.Imports)
+	// stripStability(w.Exports)
 	w.Package.Worlds.Set(name, w)
 
 	r = r.Clone()
 	r.Worlds = append(r.Worlds, w)
 
 	return r, w
 }
+
+// Strip stability from world items for serialization.
+// https://github.com/bytecodealliance/go-modules/issues/306#issuecomment-2737873621
+func stripStability(items ordered.Map[string, wit.WorldItem]) {
+	items.All()(func(name string, i wit.WorldItem) bool {
+		if ref, ok := i.(*wit.InterfaceRef); ok {
+			ref2 := *ref
+			ref2.Stability = nil
+			items.Set(name, &ref2)
+		}
+		return true
+	})
+}

wit/wit.go

@@ -116,6 +116,14 @@ func unwrap(s string) string {
 	return line
 }
 
+// newline returns either a blank string or a string with a newline.
+func newline(s string) string {
+	if s == "" {
+		return ""
+	}
+	return s + "\n"
+}
+
 // WITKind returns the WIT kind.
 func (*Resolve) WITKind() string { return "resolve" }
 
@@ -156,8 +164,23 @@ func (*Stable) WITKind() string { return "@since" }
 // WIT returns the [WIT] text format for [Stable] s.
 //
 // [WIT]: https://github.com/WebAssembly/component-model/blob/main/design/mvp/WIT.md
-func (s *Stable) WIT(_ Node, _ string) string {
+func (s *Stable) WIT(ctx Node, _ string) string {
 	var b strings.Builder
+	var w *World
+	switch ctx := ctx.(type) {
+	case worldImport:
+		w = ctx.World
+	case worldExport:
+		w = ctx.World
+	case *World:
+		w = ctx
+	}
+	if w != nil && w.Package.Name.Version != nil {
+		pv := w.Package.Name.Version
+		if pv.LessThan(s.Since) {
+			return ""
+		}
+	}
 	b.WriteString("@since(version = ")
 	b.WriteString(s.Since.String())
 	b.WriteRune(')')
@@ -256,8 +279,7 @@ func (w *World) WIT(ctx Node, name string) string {
 	var b strings.Builder
 	b.WriteString(w.Docs.WIT(nil, ""))
 	if w.Stability != nil {
-		b.WriteString(w.Stability.WIT(nil, ""))
-		b.WriteRune('\n')
+		b.WriteString(newline(w.Stability.WIT(w, "")))
 	}
 	b.WriteString("world ")
 	b.WriteString(escape(name)) // TODO: compare to w.Name?
@@ -311,7 +333,7 @@ func (ref *InterfaceRef) WIT(ctx Node, name string) string {
 	if ref.Stability == nil {
 		return ref.Interface.WIT(ctx, name)
 	}
-	return ref.Stability.WIT(ctx, "") + "\n" + ref.Interface.WIT(ctx, name)
+	return newline(ref.Stability.WIT(ctx, "")) + ref.Interface.WIT(ctx, name)
 }
 
 // WITKind returns the WIT kind.
@@ -357,8 +379,7 @@ func (i *Interface) WIT(ctx Node, name string) string {
 	default: // e.g. *Package
 		b.WriteString(i.Docs.WIT(ctx, ""))
 		if i.Stability != nil {
-			b.WriteString(i.Stability.WIT(ctx, ""))
-			b.WriteRune('\n')
+			b.WriteString(newline(i.Stability.WIT(ctx, "")))
 		}
 		b.WriteString("interface ")
 		b.WriteString(escape(name))
@@ -455,8 +476,7 @@ func (t *TypeDef) WIT(ctx Node, name string) string {
 		var b strings.Builder
 		b.WriteString(t.Docs.WIT(ctx, ""))
 		if t.Stability != nil {
-			b.WriteString(t.Stability.WIT(ctx, ""))
-			b.WriteRune('\n')
+			b.WriteString(newline(t.Stability.WIT(ctx, "")))
 		}
 		b.WriteString(t.Kind.WIT(t, name))
 		constructor := t.Constructor()
@@ -1051,8 +1071,7 @@ func (f *Function) WIT(ctx Node, name string) string {
 	if ctx != nil {
 		b.WriteString(f.Docs.WIT(ctx, ""))
 		if f.Stability != nil {
-			b.WriteString(f.Stability.WIT(ctx, ""))
-			b.WriteRune('\n')
+			b.WriteString(newline(f.Stability.WIT(ctx, "")))
 		}
 	}
 	switch ctx.(type) {