util: support inspecting namespaces of unevaluated modules

PR-URL: #20782
Reviewed-By: Ben Noordhuis <info@bnoordhuis.nl>
Reviewed-By: Guy Bedford <guybedford@gmail.com>
Reviewed-By: Ruben Bridgewater <ruben@bridgewater.de>
Reviewed-By: James M Snell <jasnell@gmail.com>

Author: devsnek

lib/util.js

@@ -629,6 +629,9 @@ function formatValue(ctx, value, recurseTimes, ln) {
 }else{
 extra='[items unknown]';
 }
+}elseif(types.isModuleNamespaceObject(value)){
+braces[0]=`[${tag}] {`;
+formatter=formatNamespaceObject;
 }else{
 // Check boxed primitives other than string with valueOf()
 // NOTE: `Date` has to be checked first!
@@ -757,6 +760,15 @@ function formatObject(ctx, value, recurseTimes, keys) {
 returnoutput;
 }
 
+functionformatNamespaceObject(ctx,value,recurseTimes,keys){
+constlen=keys.length;
+constoutput=newArray(len);
+for(vari=0;i<len;i++){
+output[i]=formatNamespaceProperty(ctx,value,recurseTimes,keys[i]);
+}
+returnoutput;
+}
+
 // The array is sparse and/or has extra keys
 functionformatSpecialArray(ctx,value,recurseTimes,keys,maxLength,valLen){
 constoutput=[];
@@ -980,8 +992,36 @@ function formatPromise(ctx, value, recurseTimes, keys) {
 returnoutput;
 }
 
+functionformatKey(ctx,key,enumerable){
+if(typeofkey==='symbol'){
+return`[${ctx.stylize(key.toString(),'symbol')}]`;
+}
+if(enumerable===false){
+return`[${key}]`;
+}
+if(keyStrRegExp.test(key)){
+returnctx.stylize(key,'name');
+}
+returnctx.stylize(strEscape(key),'string');
+}
+
+functionformatNamespaceProperty(ctx,ns,recurseTimes,key){
+letvalue;
+try{
+value=formatValue(ctx,ns[key],recurseTimes,true);
+}catch(err){
+if(errinstanceofReferenceError){
+value=ctx.stylize('<uninitialized>','special');
+}else{
+throwerr;
+}
+}
+
+return`${formatKey(ctx,key)}: ${value}`;
+}
+
 functionformatProperty(ctx,value,recurseTimes,key,array){
-letname,str;
+letstr;
 constdesc=Object.getOwnPropertyDescriptor(value,key)||
 {value: value[key],enumerable: true};
 if(desc.value!==undefined){
@@ -1003,17 +1043,8 @@ function formatProperty(ctx, value, recurseTimes, key, array) {
 if(array===1){
 returnstr;
 }
-if(typeofkey==='symbol'){
-name=`[${ctx.stylize(key.toString(),'symbol')}]`;
-}elseif(desc.enumerable===false){
-name=`[${key}]`;
-}elseif(keyStrRegExp.test(key)){
-name=ctx.stylize(key,'name');
-}else{
-name=ctx.stylize(strEscape(key),'string');
-}
 
-return`${name}: ${str}`;
+return`${formatKey(ctx,key,desc.enumerable)}: ${str}`;
 }
 
 functionreduceToSingleString(ctx,output,base,braces,addLn){

test/parallel/test-util-inspect-namespace.js

@@ -0,0 +1,22 @@
+'use strict';
+
+// Flags: --experimental-vm-modules
+
+constcommon=require('../common');
+constassert=require('assert');
+
+common.crashOnUnhandledRejection();
+
+const{ Module }=require('vm');
+const{ inspect }=require('util');
+
+(async()=>{
+constm=newModule('export const a = 1; export var b = 2');
+awaitm.link(()=>0);
+m.instantiate();
+assert.strictEqual(
+inspect(m.namespace),
+'[Module] { a: <uninitialized>, b: undefined }');
+awaitm.evaluate();
+assert.strictEqual(inspect(m.namespace),'[Module] { a: 1, b: 2 }');
+})();