TypeScript 7 VS Code extension: let extensions that serve their language through content mappers opt out of the tsserver-plugin warning #64356
Description
🔎 Search Terms
TypeScript server plugins from thewill not be loaded because TypeScript 7 is enabled globallywarnAboutTsServerPluginstypescriptServerPluginscontent mapper
🕗 Version & Regression Information
- The TypeScript 7 VS Code extension built from
packages/vscode-typescriptat f29aeb9 (main, 2026-09-16), VS Code 1.138.0, macOS 26.6 x64 - The warning and its exemption list are unchanged since the published
TypeScriptTeam.native-preview0.20260708.2
⏯ Playground Link
n/a (VS Code extension behaviour)
💻 Code
warnAboutTsServerPlugins in packages/vscode-typescript/src/extension.ts warns once per session, when js/ts.experimental.useTsgo is set at user level, for every installed extension whose manifest contributes typescriptServerPlugins:
TypeScript server plugins from the "TSRX.tsrx-vscode-plugin" extension will not be loaded because TypeScript 7 is enabled globally.
The only exemption is the hardcoded suppressedPluginExtensionIds set (github.copilot, github.copilot-chat).
An extension for a content-mapped language needs both mechanisms: a typescriptServerPlugins contribution so that VS Code's built-in TypeScript extension (TypeScript 5.9/6, tsserver) can serve its files, and a content mapper (declared in the project's tsconfig.json under contentMappers) so that TypeScript 7 can. When TypeScript 7 is enabled, the plugin is intentionally not needed: the mapper takes over. The warning is then accurate but misleading, since the extension's language works fine.
🙁 Actual behavior
Every user of such an extension who enables TypeScript 7 globally sees a warning suggesting the extension is broken under TypeScript 7, with "Disable Native Preview in Workspace" offered as a remedy, although nothing is lost.
🙂 Expected behavior
A way for an extension to declare that its language is served through content mappers on TypeScript 7, for example a per-plugin flag on the contribution ("typescriptServerPlugins": [{ "name": "...", "contentMappers": true }] or similar), which the warning would then skip, as it skips the hardcoded ids today.
Additional information about the issue
Found while wiring the TSRX VS Code extension (tsrx-org/tsrx#135); its README currently tells users to dismiss the warning with "Don't Show Again".
Activity
leonidaz commentedon Oct 1, 2026
A simpler solution may already exist. An extension that serves its language through content mappers calls
registerContentMapperson the TypeScript 7 extension's API (the "LSP Activation" section of microsoft/typescript-go#4712), with its own extension ID. TSRX does this:warnAboutTsServerPluginscould skip every extension ID that registered content mappers, as it skipssuppressedPluginExtensionIdstoday. Then extensions need no manifest flag.One timing detail: the warning check runs after the server starts and on
vscode.extensions.onDidChange. An extension usually registers right after it activates the TypeScript 7 extension. So the check would need to run again after a registration, or wait for registrations briefly.docs(vscode-plugin): plainer TypeScript 7 sections and a legacy setti…