WIP 3

lib/instrument/visitors/class.js

@@ -29,7 +29,7 @@ const {
 		createThisBinding, createArgumentsBinding, createNewTargetBinding
 	} = require('../blocks.js'),
 	{insertTrackerCodeIntoFunction} = require('../tracking.js'),
-	{visitKey, visitKeyContainer} = require('../visit.js'),
+	{visitKey, visitKeyMaybe, visitKeyContainer} = require('../visit.js'),
 	{createTempVarNode} = require('../internalVars.js'),
 	{FN_TYPE_CLASS} = require('../../shared/constants.js');
 
@@ -111,8 +111,7 @@ function visitClass(classNode, parent, key, className, state) {
 	state.isStrict = true;
 
 	// Visit `extends` clause
-	const hasSuperClass = !!classNode.superClass;
-	if (hasSuperClass) {
+	if (classNode.superClass) {
 		fn.hasSuperClass = true;
 		visitKey(classNode, 'superClass', Expression, state);
 	}
@@ -208,14 +207,13 @@ function visitClass(classNode, parent, key, className, state) {
 			createNewTargetBinding(protoThisBlock);
 			state.currentThisBlock = protoThisBlock;
 
-			// If class does not extend a super class, prototype properties will be evaluated
-			// before class constructor, so tracker needs to go in 1st proto property which has a value
 			for (const index of protoPropertyIndexes) {
-				const propNode = memberNodes[index];
-				if (!propNode.value) continue;
 				visitKey(memberNodes, index, ClassPropertyMaybePrivate, state);
-				if (!hasSuperClass && !propForTrackerNode) propForTrackerNode = propNode;
 			}
+
+			// If class does not extend a super class, prototype properties will be evaluated
+			// before class constructor, so tracker needs to go in 1st proto property
+			if (!classNode.superClass) propForTrackerNode = memberNodes[protoPropertyIndexes[0]];
 		}
 
 		// Exit function
@@ -355,7 +353,7 @@ function ClassMethodMaybePrivate(node, state, parent, key) {
 function ClassStaticPropertyOrBlock(node, state) {
 	if (node.type === 'StaticBlock') {
 		StaticBlock(node, state);
-	} else if (node.value) {
+	} else {
 		ClassPropertyMaybePrivate(node, state);
 	}
 }
@@ -369,7 +367,7 @@ function ClassStaticPropertyOrBlock(node, state) {
  */
 function ClassPropertyMaybePrivate(node, state) {
 	// Don't visit `key` as has been dealt with separately above
-	visitKey(node, 'value', Expression, state);
+	visitKeyMaybe(node, 'value', Expression, state);
 }
 
 /**
@@ -439,7 +437,9 @@ function instrumentClass(
 
 	if (propForTrackerNode) {
 		// Insert tracker into property
-		propForTrackerNode.value = t.sequenceExpression([trackerNode, propForTrackerNode.value]);
+		propForTrackerNode.value = propForTrackerNode.value
+			? t.sequenceExpression([trackerNode, propForTrackerNode.value])
+			: t.unaryExpression('void', trackerNode);
 		trackerNode = undefined;
 	} else if (!constructorNode) {
 		// Class has no constructor - create one for tracker code to be inserted in