LWC extension rewrites jsconfig.json unconditionally and watches directory creations, which causes sustained file-watcher CPU load

[laszlo-foldi-attentioncrm]

Summary

The LWC extension causes a continuous file-watcher load in large SFDX projects. Two defects combine.

1. writeSfdxJsconfig() writes jsconfig.json on every call. The function does not compare the new content with the old content.
2. The LWC client watches **/ with ignoreCreateEvents: false. The Apex and Lightning extensions use ignoreCreateEvents: true for the same purpose.

The extension writes into the workspace. The file watcher sees the write. The watcher event starts a new index operation. The index operation regenerates the LWC typings. The regeneration creates more watcher events.

All CPU figures below use the percent-of-one-core convention. The top command uses the same convention. My machine has 14 logical CPUs, thus the maximum is 1400%. The Windows Task Manager uses a different convention. It divides by the total capacity. Thus it shows a smaller number for the same load.

Defect 1: unconditional write

packages/salesforcedx-lightning-lsp-common/src/baseContext.ts

383:  const existingConfigContent = await this.fileSystemAccessor.getFileContent(jsconfigPath);
      // ...merge...
426:  jsconfigContent = JSON.stringify(mergedConfig, null, 4);
452:  await this.fileSystemAccessor.updateFileContent(jsconfigPath, jsconfigContent);

Line 383 reads the old content. Line 452 writes the new content. The code does not compare the two values.

updateForceIgnoreFile() in the same file uses the correct pattern. writeSfdxJsconfig() calls this function at line 466.

115:  const originalContent = forceignoreContent;
      // ...append patterns...
136:  if (forceignoreContent === originalContent) {
137:    return;
138:  }

Defect 2: watcher flag

Three packages create the same watcher. The LWC package is different from the other two.

// packages/salesforcedx-vscode-apex/src/languageServer.ts:234
createFileSystemWatcher('**/', true, true, false),   // only events for folder deletions

// packages/salesforcedx-vscode-lightning/src/index.ts:156
createFileSystemWatcher('**/', true, true, false),

// packages/salesforcedx-vscode-lwc/src/languageClient/clientOptions.ts:33
// need to watch for directory deletions as no events are created for contents or deleted directories
createFileSystemWatcher('**/', false, true, false)   // ignoreCreateEvents = false

The signature is (pattern, ignoreCreateEvents, ignoreChangeEvents, ignoreDeleteEvents). The comment says that the watcher observes deletions. The code also observes the creation of every directory in the workspace. https://code.visualstudio.com/api/references/vscode-api#workspace

Steps To Reproduce:

1. Open a large SFDX project in VS Code. My project has 191 LWC bundles and 496 Apex classes.

2. Make sure that files.watcherExclude does not exclude .sfdx. This is the default condition.

3. Do not use the editor for some minutes.

4. Run the PowerShell script below. The script samples the CPU time for 8 seconds. It reports both conventions.

   $cores = [Environment]::ProcessorCount
   $ids = (Get-CimInstance Win32_Process -Filter "Name='Code.exe'").ProcessId
   $t1 = @{}
   foreach ($i in $ids) {
     $p = Get-CimInstance Win32_Process -Filter "ProcessId=$i" -EA SilentlyContinue
     if ($p) { $t1[$i] = ($p.KernelModeTime + $p.UserModeTime) / 1e7 }
   }
   $sw = [Diagnostics.Stopwatch]::StartNew(); Start-Sleep -Seconds 8; $sw.Stop()
   $el = $sw.Elapsed.TotalSeconds
   foreach ($i in $ids) {
     $p = Get-CimInstance Win32_Process -Filter "ProcessId=$i" -EA SilentlyContinue
     if ($p -and $t1.ContainsKey($i)) {
       $d = (($p.KernelModeTime + $p.UserModeTime) / 1e7) - $t1[$i]
       if ($d -gt 0.05) {
         [pscustomobject]@{
           PID        = $i
           CPUsec     = [math]::Round($d, 2)
           PctOneCore = [math]::Round($d / $el * 100, 1)
           PctMachine = [math]::Round($d / ($el * $cores) * 100, 1)
         }
       }
     }
   }

5. Find the process with the highest CPUsec value.

6. Run (Get-CimInstance Win32_Process -Filter "ProcessId=<PID>").CommandLine for that process. The command line contains --utility-sub-type=node.mojom.NodeService. This process runs the file watcher.

7. Look at the modification times of force-app/main/default/lwc/jsconfig.json.

8. Look at the modification times of the files in .sfdx/typings/lwc/.

Expected result

The file watcher uses almost no CPU while the editor is idle.

The extension writes jsconfig.json only when the content changes.

Actual result

The file-watcher process keeps one core to two cores busy while the editor is idle. The process accumulated 4.9 hours of CPU time in one session.

Two measurements from the same session follow. The editor was idle for both.

Sample	Interval	CPU time used	Percent of one core	Percent of machine
1	6.00 s	7.6 s	126.6%	9.0%
2	8.01 s	16.75 s	209.2%	14.9%

The machine has 14 logical CPUs. The process uses more than one thread, thus it uses more than one core.

The extension regenerates the 5,166 .d.ts files in .sfdx/typings/lwc/. These files and jsconfig.json get new modification times again and again. The content of jsconfig.json does not change.

The extension host becomes unstable under this load. My renderer.log file has 915 entries that report an unresponsive extension host. The same log shows the exits of 14 different extension-host process IDs.

The extension host starts git.exe child processes. When the extension host exits, the child processes become orphans. I found 10 orphaned git.exe processes. They stayed blocked for two days. Because of these processes, the built-in Git view and the diff view do not work correctly. A git status command in a terminal stays fast at 265 ms to 421 ms.

Additional information

Suggested fix for defect 1

Compare the content before the write in writeSfdxJsconfig():

if (jsconfigContent === existingConfigContent) {
  continue;
}
await this.fileSystemAccessor.updateFileContent(jsconfigPath, jsconfigContent);

Suggested fix for defect 2

Set ignoreCreateEvents to true in clientOptions.ts at line 33. This value agrees with the comment. It also agrees with the Apex and Lightning packages.

createFileSystemWatcher('**/', true, true, false)

Workaround

Add files.watcherExclude for **/.sfdx/** to the workspace settings. This setting reduces the load, but it does not remove the cause.

Note on .forceignore

writeSfdxJsconfig() also fore appends two patterns to .forceignore. The patterns are **/jsconfig.json and **/.eslintrc.json. This write has the correct guard. I report it because the extension changes a file that is under source control. Maybe, the extension should be able to distinguish between developer tooling actual sources, so it does not tries to parse and deploy local configs, even if these are not even in a proper source folder or have associated *-meta.xml and related *.ts, *.js, or any other LWC specific source files with them. Check: jsconfig.json

Project Info:

Project Info

Generated: 2026-08-07T05:55:07.771Z

Metadata

sourceApiVersion: 67.0
packageDirectories: 1
namespace:

Types

Type	Components	Files	Size (KB)
ApexClass	496	1488	6364
ApexComponent	12	36	28
ApexEmailNotifications	1	1	0
ApexPage	39	117	169
ApexTrigger	35	105	30
ApprovalProcess	2	2	5
AssignmentRules	2	2	318
Audience	32	32	51
AuraDefinitionBundle	29	180	255
AutoResponseRules	2	2	2
Bot	3	9	56
CampaignInfluenceModel	1	1	0
Certificate	6	18	22
CleanDataService	3	3	57
Community	1	1	0
ConnectedApp	6	6	10
ContentAsset	5031	15093	292845
CspTrustedSite	26	26	18
CustomApplication	28	28	1440
CustomFeedFilter	3	3	1
CustomField	1	1	1
CustomHelpMenuSection	1	1	1
CustomIndex	3	3	0
CustomLabels	1	1	343
CustomMetadata	1811	1811	2084
CustomNotificationType	1	1	0
CustomObject	411	6748	8118
CustomObjectTranslation	1806	18988	11850
CustomPermission	16	16	4
CustomSite	9	9	17
CustomTab	32	32	7
Dashboard	2	2	7
DashboardFolder	1	1	1
DataCategoryGroup	3	3	6
DigitalExperience	17	51	23
DigitalExperienceBundle	1	1	1
DigitalExperienceConfig	1	1	0
Document	23	69	3117
DocumentFolder	1	1	0
DuplicateRule	11	11	20
EmailFolder	5	5	13
EmailServicesFunction	2	2	2
EmailTemplate	122	366	745
EmbeddedServiceConfig	1	1	3
EscalationRules	1	1	0
ExperienceBundle	4	449	813
ExternalClientApplication	2	2	1
ExternalCredential	2	2	3
ExternalDataSource	1	1	1
ExtlClntAppConfigurablePolicies	2	2	1
ExtlClntAppGlobalOauthSettings	2	2	3
ExtlClntAppOauthConfigurablePolicies	2	2	2
ExtlClntAppOauthSecuritySettings	2	2	1
ExtlClntAppOauthSettings	2	2	1
FlexiPage	75	75	1632
Flow	151	151	2682
FlowDefinition	93	93	16
ForecastingType	20	20	9
GenAiFunction	10	40	34
GenAiPlannerBundle	2	4	3
GenAiPlugin	3	3	12
GenAiPromptTemplate	1	1	18
GlobalValueSet	32	32	288
GlobalValueSetTranslation	142	142	1443
Group	282	282	52
HomePageLayout	1	1	1
IframeWhiteListUrlSettings	1	1	0
InstalledPackage	14	14	4
Layout	402	402	1847
LeadConvertSettings	1	1	5
Letterhead	1	1	1
LightningComponentBundle	191	899	2973
LightningMessageChannel	3	3	1
ListView	1	1	1
ManagedContentType	3	3	5
ManagedTopics	5	5	1
MatchingRules	5	5	9
MessagingChannel	1	1	4
MilestoneType	8	8	2
NamedCredential	6	6	4
NavigationMenu	15	15	24
Network	4	4	13
NetworkBranding	5	15	54
NotificationTypeConfig	1	1	22
PathAssistant	11	11	11
PermissionSet	86	86	1585
PermissionSetGroup	3	3	2
PresenceUserConfig	1	1	1
Profile	27	27	23939
ProfilePasswordPolicy	17	17	11
ProfileSessionSetting	16	16	7
Prompt	6	6	11
Queue	198	198	132
QueueRoutingConfig	3	3	1
QuickAction	120	120	151
RemoteSiteSetting	21	21	6
Report	22	22	53
ReportFolder	6	6	3
ReportType	90	90	2050
Role	2383	2383	1153
SamlSsoConfig	3	3	8
Settings	125	125	1739
SharingRules	189	189	49
SharingSet	1	1	1
SiteDotCom	4	12	4706
StandardValueSet	38	38	99
StandardValueSetTranslation	172	172	858
StaticResource	45	2627	51491
Territory2	127	127	68
Territory2Model	2	2	0
Territory2Rule	83	83	45
Territory2Type	6	6	1
TimeSheetTemplate	1	1	1
TopicsForObjects	146	146	32
Translations	21	21	17879
UserProvisioningConfig	1	1	0
WebStoreTemplate	4	4	5
Workflow	7	7	9

Org

Key	Value
Org type	production
Source tracking	false
SourceMember count	N/A

Settings

Setting	Value
salesforcedx-vscode-metadata.showSuccessNotification	true
salesforcedx-vscode-metadata.sourceTracking.pollingIntervalSeconds	0
salesforcedx-vscode-core.push-or-deploy-on-save.enabled	false
salesforcedx-vscode-core.push-or-deploy-on-save.ignoreConflictsOnPush	false
salesforcedx-vscode-core.detectConflictsForDeployAndRetrieve	false
salesforcedx-vscode-core.clearOutputTab	false
salesforcedx-vscode-core.show-cli-success-msg	true
salesforcedx-vscode-core.telemetry.enabled	false
salesforcedx-vscode-core.enable-sobject-refresh-on-startup	true
salesforcedx-vscode-core.telemetry-tag
salesforcedx-vscode-salesforcedx.enableLocalTraces	false
salesforcedx-vscode-salesforcedx.enableConsoleTraces	false
salesforcedx-vscode-salesforcedx.enableFileTraces	false
salesforcedx-vscode-apex.java.home	C:\Program Files\Java\jdk-25.0.2

Environment

Key	Value
Salesforce CLI	@salesforce/cli/2.142.7 win32-x64 node-v24.14.1
Java	java 25.0.2 2026-01-20 LTS
Editor	Visual Studio Code
VS Code	1.132.0
Node	v24.18.0
OS	Windows_NT 10.0.26200

Extensions (Salesforce)

Extension	Version
salesforce.apex-language-server-extension	0.8.0
salesforce.mule-dx-api-component	4.21.0
salesforce.mule-dx-apikit-component	1.4.0
salesforce.mule-dx-data-weave-client	2.13.0
salesforce.mule-dx-dependencies	1.7.1
salesforce.mule-dx-extension-pack	1.24.1
salesforce.mule-dx-mule-dev-component	3.31.4
salesforce.mule-dx-munit-component	1.3.13
salesforce.mule-dx-runtime	1.2.0
salesforce.mule-dx-vscode	5.18.3
salesforce.salesforce-vscode-slds	2.0.12
salesforce.salesforcedx-metadata-visualizer-vscode	1.2.0
salesforce.salesforcedx-vscode	67.7.1
salesforce.salesforcedx-vscode-apex	67.7.1
salesforce.salesforcedx-vscode-apex-log	67.7.1
salesforce.salesforcedx-vscode-apex-replay-debugger	67.7.1
salesforce.salesforcedx-vscode-apex-testing	67.7.1
salesforce.salesforcedx-vscode-core	67.7.1
salesforce.salesforcedx-vscode-expanded	67.7.1
salesforce.salesforcedx-vscode-lightning	67.7.1
salesforce.salesforcedx-vscode-lwc	67.7.1
salesforce.salesforcedx-vscode-metadata	67.7.1
salesforce.salesforcedx-vscode-org	67.7.1
salesforce.salesforcedx-vscode-org-browser	67.7.1
salesforce.salesforcedx-vscode-services	67.7.1
salesforce.salesforcedx-vscode-soql	67.7.1
salesforce.salesforcedx-vscode-ui-preview	1.4.0
salesforce.salesforcedx-vscode-visualforce	67.7.1
salesforce.sfdx-code-analyzer-vscode	1.21.0

Most recent version of the extensions where this was working:

Not sure, had these issues for a while, but now the frustration accumulated so bad, I had to see what's under the hood. I think salesforcedx-lightning-lsp-common was shipped with this issue, as packages/salesforcedx-lightning-lsp-common/src/baseContext.ts always worked as described, from first commit: 3352a85, and packages/salesforcedx-vscode-lwc/src/languageClient/clientOptions.ts had the same issue from it's first commit too 54f6656

[svc-idee-bot]

Thank you for filing this issue. We appreciate your feedback and will review the issue as soon as possible. Remember, however, that GitHub isn't a mechanism for receiving support under any agreement or SLA. If you require immediate assistance, contact Salesforce Customer Support.

[git2gus]

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