Support class field declarations.

Fixes: estools#443

escodegen.js

@@ -2161,6 +2161,10 @@
             return join(result, fragment);
         },
 
+        PrivateIdentifier: function(expr, precedence, flags) {
+            return toSourceNodeWhenNeeded('#' + expr.name, expr);
+        },
+
         Property: function (expr, precedence, flags) {
             if (expr.kind === 'get' || expr.kind === 'set') {
                 return [
@@ -2192,6 +2196,22 @@
             ];
         },
 
+        PropertyDefinition: function(expr, precedence, flags) {
+            var keywords = [];
+            if (expr.static) {
+                keywords.push('static');
+            }
+
+            return join(keywords, [
+                this.generatePropertyKey(expr.key, expr.computed),
+                space,
+                '=',
+                space,
+                this.generateExpression(expr.value, Precedence.Assignment, E_TTT),
+                this.semicolon(flags),
+            ]);
+        },
+
         ObjectExpression: function (expr, precedence, flags) {
             var multiline, result, fragment, that = this;
 
@@ -2513,6 +2533,9 @@
             return generateVerbatim(expr, precedence);
         }
 
+        if (!(type in this)) {
+            throw new Error('Unknown node type: ' + type);
+        }
         result = this[type](expr, precedence, flags);
 
 

package.json

@@ -38,7 +38,7 @@
         "source-map": "~0.6.1"
     },
     "devDependencies": {
-        "acorn": "^8.0.4",
+        "acorn": "^8.2.0",
         "bluebird": "^3.4.7",
         "bower-registry-client": "^1.0.0",
         "chai": "^4.2.0",