Add configuration option requireConfig

.gitignore

@@ -1,5 +1,6 @@
 coverage/
 node_modules/
+/test/.testremarkrc.json
 *.log
 *.d.ts
 *.tgz

lib/index.js

@@ -24,8 +24,18 @@
  *   This can be used to ship a processor with your package, to be used if no
  *   processor is found locally.
  *   If this isn’t passed, a warning is shown if `processorName` can’t be found.
+ * @property {string} configurationSection
+ *   This option will be used to give the client a hint of which configuration
+ *   section to use.
+ *   For example VSCode extensions use this to pick only settings that use this
+ *   as a prefix in order to prevent conflicts and reduce the amount of data
+ *   sent to the language server.
  *
  * @typedef {EngineFields & LanguageServerFields} Options
+ *
+ * @typedef UnifiedLanguageServerSettings
+ * @property {boolean} [requireConfig=false]
+ *   If true, files will only be checked if a configuration file is present.
  */
 
 import path from 'node:path'
@@ -42,6 +52,7 @@ import {
   CodeActionKind,
   Diagnostic,
   DiagnosticSeverity,
+  DidChangeConfigurationNotification,
   Position,
   ProposedFeatures,
   Range,
@@ -122,6 +133,7 @@ function lspDocumentToVfile(document, cwd) {
  *   Configuration for `unified-engine` and the language server.
  */
 export function createUnifiedLanguageServer({
+  configurationSection,
   ignoreName,
   packageField,
   pluginPrefix,
@@ -135,14 +147,49 @@ export function createUnifiedLanguageServer({
   const documents = new TextDocuments(TextDocument)
   /** @type {Set<string>} */
   const workspaces = new Set()
+  /** @type {UnifiedLanguageServerSettings} */
+  const globalSettings = {requireConfig: false}
+  /** @type {Map<string, Promise<UnifiedLanguageServerSettings>>} */
+  const documentSettings = new Map()
   let hasWorkspaceFolderCapability = false
+  let hasConfigurationCapability = false
+
+  /**
+   * @param {string} scopeUri
+   * @returns {Promise<UnifiedLanguageServerSettings>}
+   */
+  async function getDocumentSettings(scopeUri) {
+    if (!hasConfigurationCapability) {
+      return globalSettings
+    }
+
+    let result = documentSettings.get(scopeUri)
+    if (!result) {
+      result = connection.workspace
+        .getConfiguration({scopeUri, section: configurationSection})
+        .then(
+          /** @param {Record<string, unknown>} raw */
+          (raw) => ({requireConfig: Boolean(raw.requireConfig)})
+        )
+      documentSettings.set(scopeUri, result)
+    }
+
+    return result
+  }
 
   /**
    * @param {string} cwd
    * @param {VFile[]} files
    * @param {boolean} alwaysStringify
+   * @param {boolean} ignoreUnconfigured
+   * @returns {Promise<VFile[]>}
    */
-  async function processWorkspace(cwd, files, alwaysStringify) {
+  async function processWorkspace(
+    cwd,
+    files,
+    alwaysStringify,
+    ignoreUnconfigured
+  ) {
     /** @type {EngineOptions['processor']} */
     let processor
 
@@ -190,6 +237,7 @@ export function createUnifiedLanguageServer({
           cwd,
           files,
           ignoreName,
+          ignoreUnconfigured,
           packageField,
           pluginPrefix,
           plugins,
@@ -233,6 +281,8 @@ export function createUnifiedLanguageServer({
       .sort((a, b) => b.length - a.length)
     /** @type {Map<string, Array<VFile>>} */
     const workspacePathToFiles = new Map()
+    /** @type {Map<string, Array<VFile>>} */
+    const workspacePathToFilesRequireConfig = new Map()
 
     await Promise.all(
       textDocuments.map(async (textDocument) => {
@@ -269,18 +319,28 @@ export function createUnifiedLanguageServer({
 
         if (!cwd) return
 
+        const configuration = await getDocumentSettings(textDocument.uri)
+
         const file = lspDocumentToVfile(textDocument, cwd)
 
-        const files = workspacePathToFiles.get(cwd) || []
-        workspacePathToFiles.set(cwd, [...files, file])
+        const filesMap = configuration.requireConfig
+          ? workspacePathToFilesRequireConfig
+          : workspacePathToFiles
+        const files = filesMap.get(cwd) || []
+        files.push(file)
+        filesMap.set(cwd, files)
       })
     )
 
     /** @type {Array<Promise<Array<VFile>>>} */
     const promises = []
 
     for (const [cwd, files] of workspacePathToFiles) {
-      promises.push(processWorkspace(cwd, files, alwaysStringify))
+      promises.push(processWorkspace(cwd, files, alwaysStringify, false))
+    }
+
+    for (const [cwd, files] of workspacePathToFilesRequireConfig) {
+      promises.push(processWorkspace(cwd, files, alwaysStringify, true))
     }
 
     const listsOfFiles = await Promise.all(promises)
@@ -324,6 +384,9 @@ export function createUnifiedLanguageServer({
       workspaces.add(event.rootUri)
     }
 
+    hasConfigurationCapability = Boolean(
+      event.capabilities.workspace && event.capabilities.workspace.configuration
+    )
     hasWorkspaceFolderCapability = Boolean(
       event.capabilities.workspace &&
         event.capabilities.workspace.workspaceFolders
@@ -345,6 +408,10 @@ export function createUnifiedLanguageServer({
   })
 
   connection.onInitialized(() => {
+    if (hasConfigurationCapability) {
+      connection.client.register(DidChangeConfigurationNotification.type)
+    }
+
     if (hasWorkspaceFolderCapability) {
       connection.workspace.onDidChangeWorkspaceFolders((event) => {
         for (const workspace of event.removed) {
@@ -399,13 +466,30 @@ export function createUnifiedLanguageServer({
       version,
       diagnostics: []
     })
+    documentSettings.delete(uri)
   })
 
   // Check everything again if the file system watched by the client changes.
   connection.onDidChangeWatchedFiles(() => {
     checkDocuments(...documents.all())
   })
 
+  connection.onDidChangeConfiguration((change) => {
+    if (hasConfigurationCapability) {
+      // Reset all cached document settings
+      documentSettings.clear()
+    } else {
+      globalSettings.requireConfig = Boolean(
+        /** @type {Omit<typeof change, 'settings'> & { settings: Record<string, unknown> }} */ (
+          change
+        ).settings.requireConfig
+      )
+    }
+
+    // Revalidate all open text documents
+    checkDocuments(...documents.all())
+  })
+
   connection.onCodeAction((event) => {
     /** @type {CodeAction[]} */
     const codeActions = []

readme.md

@@ -21,6 +21,7 @@ Create a **[language server][]** based on **[unified][]** ecosystems.
 *   [Examples](#examples)
 *   [Types](#types)
 *   [Language Server features](#language-server-features)
+    *   [Configuration](#configuration)
 *   [Compatibility](#compatibility)
 *   [Related](#related)
 *   [Contribute](#contribute)
@@ -205,6 +206,11 @@ server features:
     Any messages collected are published to the client using
     `textDocument/publishDiagnostics`.
 
+### Configuration
+
+*   `requireConfig` (default: `false`)
+    — If true, files will only be checked if a configuration file is present.
+
 ## Compatibility
 
 Projects maintained by the unified collective are compatible with all maintained

test/code-actions.js

@@ -1,6 +1,7 @@
 import {createUnifiedLanguageServer} from 'unified-language-server'
 
 createUnifiedLanguageServer({
+  configurationSection: 'remark',
   processorName: 'remark',
   processorSpecifier: 'remark',
   plugins: [warn]

test/folder/remark-with-cwd.js

@@ -1,6 +1,7 @@
 import {createUnifiedLanguageServer} from 'unified-language-server'
 
 createUnifiedLanguageServer({
+  configurationSection: 'remark',
   processorName: 'remark',
   processorSpecifier: 'remark',
   plugins: [warn]