with statements WIP 3

lib/instrument/blocks.js

@@ -199,6 +199,7 @@ function getOrCreateExternalVar(externalVars, block, varName, bindingOrExternalV
 			varNode: bindingOrExternalVar.varNode,
 			isReadFrom: false,
 			isAssignedTo: false,
+			isNameLocked: false,
 			argNames: bindingOrExternalVar.argNames,
 			trails: []
 		};

lib/instrument/visitors/function.js

@@ -728,6 +728,7 @@ function createFunctionInfoFunction(fn, scopes, astJson, fnInfoVarNode, state) {
 				return {
 					isReadFrom: varProps.isReadFrom || undefined,
 					isAssignedTo: varProps.isAssignedTo || undefined,
+					isNameLocked: varProps.isNameLocked || undefined,
 					trails: varProps.trails
 				};
 			})

lib/instrument/visitors/identifier.js

@@ -81,7 +81,7 @@ function ThisExpression(node, state) {
 	// Ignore if internal to function, unless in class constructor or prototype class property
 	// of class with super class.
 	if (block.id < fn.id) {
-		recordExternalVar(binding, block, 'this', fn, [...state.trail], true, false, state);
+		recordExternalVar(binding, block, 'this', fn, [...state.trail], true, false, false, state);
 	} else if (fn.hasSuperClass) {
 		createArrayOrPush(fn.internalVars, 'this', [...state.trail]);
 	}
@@ -105,7 +105,7 @@ function NewTargetExpression(node, state) {
 	const block = state.currentThisBlock;
 	if (block.id < fn.id) {
 		recordExternalVar(
-			block.bindings['new.target'], block, 'new.target', fn, [...state.trail], true, false, state
+			block.bindings['new.target'], block, 'new.target', fn, [...state.trail], true, false, false, state
 		);
 	}
 }
@@ -148,7 +148,7 @@ function visitIdentifier(node, varName, isReadFrom, isAssignedTo, state) {
 function resolveIdentifierInSecondPass(node, block, varName, fn, isReadFrom, isAssignedTo, state) {
 	state.secondPass(
 		resolveIdentifier,
-		node, block, varName, fn, [...state.trail], isReadFrom, isAssignedTo, state.isStrict, state
+		node, block, varName, fn, [...state.trail], isReadFrom, isAssignedTo, false, state.isStrict, state
 	);
 }
 
@@ -161,14 +161,30 @@ function resolveIdentifierInSecondPass(node, block, varName, fn, isReadFrom, isA
  * @param {Array<string|number>} trail - Trail
  * @param {boolean} isReadFrom - `true` if variable is read from
  * @param {boolean} isAssignedTo - `true` if variable is assigned to
+ * @param {boolean} isBehindWith - `true` if variable may be shadowed by a `with () {}` statement
  * @param {boolean} isStrict - `true` if variable used in strict mode
  * @param {Object} state - State object
  * @returns {undefined}
  */
-function resolveIdentifier(node, block, varName, fn, trail, isReadFrom, isAssignedTo, isStrict, state) {
+function resolveIdentifier(
+	node, block, varName, fn, trail, isReadFrom, isAssignedTo, isBehindWith, isStrict, state
+) {
 	// Find binding
-	let binding;
+	let binding,
+		bindingVarName = varName,
+		isWithBinding = false;
 	do {
+		// Check for a `with () {}` block which can intercept any variable
+		if (block.bindings.with) {
+			// Ignore `with () {}` blocks internal to function
+			if (block.id >= fn.id) continue;
+
+			binding = block.bindings.with;
+			bindingVarName = 'with';
+			isWithBinding = true;
+			break;
+		}
+
 		binding = block.bindings[varName];
 	} while (!binding && (block = block.parent)); // eslint-disable-line no-cond-assign
 
@@ -188,7 +204,8 @@ function resolveIdentifier(node, block, varName, fn, trail, isReadFrom, isAssign
 	}
 
 	// Record external var
-	if (isAssignedTo && binding.isConst) {
+	const bindingIsAssignedTo = isAssignedTo && !isWithBinding;
+	if (bindingIsAssignedTo && binding.isConst) {
 		// Record const violation
 		fn.amendments.push({
 			type: binding.isSilentConst && !isStrict
@@ -204,7 +221,16 @@ function resolveIdentifier(node, block, varName, fn, trail, isReadFrom, isAssign
 		isAssignedTo = false;
 	}
 
-	recordExternalVar(binding, block, varName, fn, trail, isReadFrom, isAssignedTo, state);
+	recordExternalVar(
+		binding, block, bindingVarName, fn, trail, isReadFrom, bindingIsAssignedTo, isBehindWith, state
+	);
+
+	// If is a `with () {}` block, continue to search for bindings further down the scope chain
+	if (isWithBinding) {
+		resolveIdentifier(
+			node, block.parent, varName, fn, trail, isReadFrom, isAssignedTo, true, isStrict, state
+		);
+	}
 }
 
 /**
@@ -216,14 +242,18 @@ function resolveIdentifier(node, block, varName, fn, trail, isReadFrom, isAssign
  * @param {Array<string|number>} trail - Trail
  * @param {boolean} isReadFrom - `true` if variable is read from
  * @param {boolean} isAssignedTo - `true` if variable is assigned to
+ * @param {boolean} isBehindWith - `true` if variable may be shadowed by a `with () {}` statement
  * @param {Object} state - State object
  * @returns {undefined}
  */
-function recordExternalVar(binding, block, varName, fn, trail, isReadFrom, isAssignedTo, state) {
+function recordExternalVar(
+	binding, block, varName, fn, trail, isReadFrom, isAssignedTo, isBehindWith, state
+) {
 	activateBlock(block, state);
 	activateBinding(binding, varName);
 	const externalVar = getOrCreateExternalVar(fn.externalVars, block, varName, binding);
 	if (isReadFrom) externalVar.isReadFrom = true;
 	if (isAssignedTo) externalVar.isAssignedTo = true;
-	externalVar.trails.push(trail);
+	if (isBehindWith) externalVar.isNameLocked = true;
+	if (varName !== 'with') externalVar.trails.push(trail);
 }

lib/serialize/parseFunction.js

@@ -81,7 +81,11 @@ module.exports = function parseFunction(
 			blockName,
 			vars: mapValues(vars, (varProps, varName) => {
 				externalVars[varName] = [];
-				return {isReadFrom: !!varProps.isReadFrom, isAssignedTo: !!varProps.isAssignedTo};
+				return {
+					isReadFrom: !!varProps.isReadFrom,
+					isAssignedTo: !!varProps.isAssignedTo,
+					isNameLocked: !!varProps.isNameLocked
+				};
 			})
 		});
 	}
@@ -865,11 +869,15 @@ function resolveFunctionInfo(
 		const {blockId} = scope;
 		if (blockId < fnId) {
 			// External var
-			for (const [varName, {isReadFrom, isAssignedTo, trails}] of Object.entries(scope.vars)) {
+			for (
+				const [varName, {isReadFrom, isAssignedTo, isNameLocked, trails}]
+				of Object.entries(scope.vars)
+			) {
 				if (isNestedFunction) {
 					const scopeDefVar = scopeDefs.get(blockId).vars[varName];
 					if (isReadFrom) scopeDefVar.isReadFrom = true;
 					if (isAssignedTo) scopeDefVar.isAssignedTo = true;
+					if (isNameLocked) scopeDefVar.isNameLocked = true;
 				}
 
 				externalVars[varName].push(...trailsToNodes(fnNode, trails, varName));