Fix merging

Author: mhegazy

src/emitter.ts

@@ -607,7 +607,7 @@ export function emitWebIDl(webidl: Browser.WebIdl, flavor: Flavor) {
             }
             const requiredModifier = !p.required || p.required === "1" ? "" : "?";
             pType = p.nullable ? makeNullable(pType) : pType;
-            const readOnlyModifier = p["read-only"] && prefix === "" ? "readonly " : "";
+            const readOnlyModifier = p["read-only"] === 1 && prefix === "" ? "readonly " : "";
             printLine(`${prefix}${readOnlyModifier}${p.name}${requiredModifier}: ${pType};`);
         }
     }
@@ -801,9 +801,9 @@ export function emitWebIDl(webidl: Browser.WebIdl, flavor: Flavor) {
 
         printer.printLine(`interface ${processInterfaceType(i, processedIName)}`);
 
-        const finalExtends = [i.extends || "Object"].concat(i.implements || [])
+        const finalExtends = distinct([i.extends || "Object"].concat(i.implements || [])
             .filter(i => i !== "Object")
-            .map(processIName);
+            .map(processIName));
 
         if (finalExtends && finalExtends.length) {
             printer.print(` extends ${finalExtends.join(", ")}`);

src/helpers.ts

@@ -28,7 +28,7 @@ export function filterProperties<T>(obj: Record<string, T>, fn: (o: T) => boolea
 
 export function merge<T>(src: T, target: T): T {
     if (typeof src !== "object" || typeof target !== "object") {
-        return src;
+        return target;
     }
     for (const k in target) {
         if (Object.getOwnPropertyDescriptor(target, k)) {
@@ -42,7 +42,7 @@ export function merge<T>(src: T, target: T): T {
                     if (Array.isArray(srcProp) !== Array.isArray(targetProp)) {
                         throw new Error("Mismatch on property: " + k + JSON.stringify(targetProp));
                     }
-                    merge(src[k], target[k]);
+                    src[k] = merge(src[k], target[k]);
                 }
             }
             else {