Resolve definitions referencing unopened files (#294)

Closes #262

.changeset/resolve-unreferenced-definitions.md

@@ -0,0 +1,5 @@
+---
+vscode-mdx: patch
+---
+
+Resolve definitions referencing unopened files.

packages/language-server/lib/convert.js

@@ -18,8 +18,6 @@
  * @typedef {import('vscode-languageserver-textdocument').TextDocument} TextDocument
  */
 
-import {pathToFileURL} from 'node:url'
-
 import {
   CompletionItemKind,
   DiagnosticSeverity,
@@ -31,7 +29,7 @@ import {
   SymbolKind
 } from 'vscode-languageserver'
 
-import {documents} from './documents.js'
+import {getOrReadDocByFileName} from './documents.js'
 
 /**
  * Convert a TypeScript script element kind to a Monaco completion kind.
@@ -285,7 +283,7 @@ function convertRelatedInformation(relatedInformation) {
       continue
     }
 
-    const related = documents.get(info.file.fileName)
+    const related = getOrReadDocByFileName(info.file.fileName)
 
     if (!related) {
       continue
@@ -368,12 +366,11 @@ export function definitionInfoToLocationLinks(info) {
   /** @type {LocationLink[]} */
   const locationLinks = []
   for (const entry of info) {
-    const url = String(pathToFileURL(entry.fileName))
-    const entryDoc = documents.get(url)
+    const entryDoc = getOrReadDocByFileName(entry.fileName)
     if (entryDoc) {
       locationLinks.push(
         LocationLink.create(
-          url,
+          entryDoc.uri,
           textSpanToRange(entryDoc, entry.textSpan),
           textSpanToRange(entryDoc, entry.textSpan)
         )

packages/language-server/lib/documents.js

@@ -1,3 +1,4 @@
+import fs from 'node:fs'
 import {pathToFileURL} from 'node:url'
 
 import {isMdx} from '@mdx-js/language-service'
@@ -12,7 +13,8 @@ export const documents = new TextDocuments(TextDocument)
 /**
  * Return a document based on its file name.
  *
- * Documents are stored using a file URL. This function allows to do a lookup by file name instead.
+ * Documents are stored using a file URL. This function allows to do a lookup by
+ * file name instead. The document will only be returned if it’s open.
  *
  * @param {string} fileName
  *   The file name to lookup.
@@ -23,6 +25,40 @@ export function getDocByFileName(fileName) {
   return documents.get(String(pathToFileURL(fileName)))
 }
 
+/**
+ * Return a document based on its file name.
+ *
+ * Documents are stored using a file URL. This function allows to do a lookup by
+ * file name instead. If the file hasn’t been opened, it will be read from the
+ * file system.
+ *
+ * @param {string} fileName
+ *   The file name to lookup.
+ * @returns {TextDocument | undefined}
+ *   The text document that matches the filename.
+ */
+export function getOrReadDocByFileName(fileName) {
+  const doc = getDocByFileName(fileName)
+  if (doc) {
+    return doc
+  }
+
+  let content
+  try {
+    content = fs.readFileSync(fileName, 'utf8')
+  } catch {
+    return
+  }
+
+  return TextDocument.create(
+    String(pathToFileURL(fileName)),
+    // The language ID doesn’t really matter for our use case.
+    'plaintext',
+    0,
+    content
+  )
+}
+
 /**
  * Get a document, but only if it’s an MDX document.
  *

packages/language-server/lib/language-service-manager.js

@@ -13,7 +13,11 @@ import {fileURLToPath, pathToFileURL} from 'node:url'
 import {createMdxLanguageService} from '@mdx-js/language-service'
 
 import {loadPlugins} from './configuration.js'
-import {documents, getDocByFileName} from './documents.js'
+import {
+  documents,
+  getDocByFileName,
+  getOrReadDocByFileName
+} from './documents.js'
 
 /**
  * Create a function for getting a script snapshot based on a TypeScript module.
@@ -24,17 +28,11 @@ import {documents, getDocByFileName} from './documents.js'
  */
 function createGetScriptSnapshot(ts) {
   return (fileName) => {
-    const doc = getDocByFileName(fileName)
+    const doc = getOrReadDocByFileName(fileName)
 
     if (doc) {
       return ts.ScriptSnapshot.fromString(doc.getText())
     }
-
-    const text = ts.sys.readFile(fileName)
-
-    if (text) {
-      return ts.ScriptSnapshot.fromString(text)
-    }
   }
 }
 

packages/language-server/tests/definitions.test.js

@@ -76,37 +76,33 @@ test('resolve cross-file definitions in ESM if the other file was previously ope
   ])
 })
 
-test(
-  'resolve cross-file definitions in ESM if the other file is unopened',
-  {skip: true},
-  async () => {
-    await connection.sendRequest(InitializeRequest.type, {
-      processId: null,
-      rootUri: null,
-      capabilities: {}
-    })
-
-    const {uri} = await openTextDocument(connection, 'node16/b.mdx')
-    const result = await connection.sendRequest(DefinitionRequest.type, {
-      position: {line: 0, character: 10},
-      textDocument: {uri}
-    })
-
-    assert.deepEqual(result, [
-      {
-        targetRange: {
-          start: {line: 1, character: 16},
-          end: {line: 1, character: 17}
-        },
-        targetSelectionRange: {
-          start: {line: 1, character: 16},
-          end: {line: 1, character: 17}
-        },
-        targetUri: fixtureUri('node16/a.mdx')
-      }
-    ])
-  }
-)
+test('resolve cross-file definitions in ESM if the other file is unopened', async () => {
+  await connection.sendRequest(InitializeRequest.type, {
+    processId: null,
+    rootUri: null,
+    capabilities: {}
+  })
+
+  const {uri} = await openTextDocument(connection, 'node16/b.mdx')
+  const result = await connection.sendRequest(DefinitionRequest.type, {
+    position: {line: 0, character: 10},
+    textDocument: {uri}
+  })
+
+  assert.deepEqual(result, [
+    {
+      targetRange: {
+        start: {line: 1, character: 16},
+        end: {line: 1, character: 17}
+      },
+      targetSelectionRange: {
+        start: {line: 1, character: 16},
+        end: {line: 1, character: 17}
+      },
+      targetUri: fixtureUri('node16/a.mdx')
+    }
+  ])
+})
 
 test('resolve markdown link references', async () => {
   await connection.sendRequest(InitializeRequest.type, {

packages/language-server/tests/diagnostics.test.js

@@ -8,6 +8,7 @@ import {InitializeRequest} from 'vscode-languageserver'
 
 import {
   createConnection,
+  fixtureUri,
   openTextDocument,
   waitForDiagnostics
 } from './utils.js'
@@ -48,7 +49,18 @@ test('type errors', async () => {
           start: {line: 6, character: 15},
           end: {line: 6, character: 21}
         },
-        relatedInformation: [],
+        relatedInformation: [
+          {
+            location: {
+              range: {
+                end: {line: 12, character: 2},
+                start: {line: 11, character: 4}
+              },
+              uri: fixtureUri('node16/type-errors.mdx')
+            },
+            message: "'count' is declared here."
+          }
+        ],
         severity: 4,
         tags: []
       },
@@ -57,10 +69,21 @@ test('type errors', async () => {
         message:
           "Property 'counter' may not exist on type 'Props'. Did you mean 'count'?",
         range: {
-          end: {line: 14, character: 58},
-          start: {line: 14, character: 51}
+          start: {line: 14, character: 51},
+          end: {line: 14, character: 58}
         },
-        relatedInformation: [],
+        relatedInformation: [
+          {
+            location: {
+              range: {
+                start: {line: 11, character: 4},
+                end: {line: 12, character: 2}
+              },
+              uri: fixtureUri('node16/type-errors.mdx')
+            },
+            message: "'count' is declared here."
+          }
+        ],
         severity: 4,
         tags: []
       }