Fix statement codegen for quote

Author: NeilKleistGao

shared/src/main/scala/mlscript/JSBackend.scala

@@ -308,12 +308,7 @@ abstract class JSBackend(allowUnresolvedSymbols: Bool) {
       else Blk(stmts.map {
         case t: Term =>
           desugarQuote(t)(blkScope, isQuoted, freeVars)
-        case nd @ NuFunDef(isLetRec, nme, symbol, tparams, rhs) => // * TODO: other cases in addition to let?
-          NuFunDef(isLetRec, nme, symbol, tparams, rhs match {
-            case L(t) => L(desugarQuote(t)(blkScope, isQuoted, freeVars))
-            case R(t) => R(t)
-          })(nd.declareLoc, nd.virtualLoc, nd.mutLoc, nd.signature, nd.outer, nd.genField, nd.annotations)
-        case s => throw CodeGenError(s"statement $s is not supported in quasiquotes")
+        case s => desugarStatementForQuote(s)(blkScope, isQuoted, freeVars)
       })
     case Tup(eles) =>
       def toVar(b: Bool) = if (b) Var("true") else Var("false")
@@ -354,6 +349,25 @@ abstract class JSBackend(allowUnresolvedSymbols: Bool) {
       throw CodeGenError("this quote syntax is not supported yet.")
   }
 
+  private def desugarStatementForQuote(s: Statement)(implicit scope: Scope, isQuoted: Bool, freeVars: FreeVars): Statement = s match {
+    case nd @ NuFunDef(isLetRec, nme, symbol, tparams, rhs) =>
+      NuFunDef(isLetRec, nme, symbol, tparams, rhs match {
+        case L(t) => L(desugarQuote(t))
+        case R(t) => R(t)
+      })(nd.declareLoc, nd.virtualLoc, nd.mutLoc, nd.signature, nd.outer, nd.genField)
+    case nt @ NuTypeDef(kind, nme, tparams, params, ctor, sig, parents, superAnnot, thisAnnot, TypingUnit(body)) =>
+      NuTypeDef(kind, nme, tparams, params, ctor.map(c => desugarStatementForQuote(c) match {
+        case c: Constructor => c
+        case _ => die
+      }), sig, parents.map(p => desugarQuote(p)), superAnnot, thisAnnot, TypingUnit(body.map(s => desugarStatementForQuote(s))))(nt.declareLoc, nt.abstractLoc)
+    case Constructor(ps, body) => Constructor(ps, desugarQuote(body) match {
+      case b: Blk => b
+      case _ => die
+    })
+    case t: Term => desugarQuote(t)
+    case _: LetS | _: DataDefn | _: DatatypeDefn | _: TypeDef | _: Def => die // * Impossible. newDef is true
+  }
+
   /**
     * Translate MLscript terms into JavaScript expressions.
     */

shared/src/test/diff/qq/Codegen.mls

@@ -372,3 +372,30 @@ x `=>
     `0
   v.value
 //│ Code[forall 'a. 'a -> 'a, ??y & ~??x]
+
+:ne
+x `=>
+  class A(y: Code[Int, nothing]) {
+    val z = x `+ y
+  }
+  A(`0).z
+//│ Code[Int -> Int, nothing]
+
+:ne
+x `=>
+  class A() {
+    constructor() {
+      log(x)
+    }
+  }
+  new A(), x
+//│ Code[forall 'a. 'a -> 'a, nothing]
+
+class Foo(x: Code[Int, anything])
+//│ class Foo(x: Code[Int, anything])
+
+:ne
+x `=>
+  class B() extends Foo(x)
+  `x
+//│ Code[forall 'a. (Int & 'a) -> 'a, nothing]