Refactor to use unist-util-lsp

Closes GH-56.

Reviewed-by: Titus Wormer <tituswormer@gmail.com>

lib/index.js

@@ -1,6 +1,4 @@
 /**
- * @typedef {import('unist').Point} Point
- * @typedef {import('unist').Position} UnistPosition
  * @typedef {import('vfile-message').VFileMessage} VFileMessage
  * @typedef {import('unified-engine').Options} EngineOptions
  * @typedef {Pick<
@@ -36,6 +34,7 @@ import {fileURLToPath} from 'node:url'
 import {findUp, pathExists} from 'find-up'
 import {loadPlugin} from 'load-plugin'
 import {engine} from 'unified-engine'
+import {fromPosition} from 'unist-util-lsp'
 import {VFile} from 'vfile'
 import {
   createConnection,
@@ -52,52 +51,6 @@ import {
 } from 'vscode-languageserver/node.js'
 import {TextDocument} from 'vscode-languageserver-textdocument'
 
-/**
- * Convert a unist point to a language server protocol position.
- *
- * @param {Point} point
- * @returns {Position}
- */
-function unistPointToLspPosition(point) {
-  return Position.create(point.line - 1, point.column - 1)
-}
-
-/**
- * @param {Point|null|undefined} point
- * @returns {boolean}
- */
-function isValidUnistPoint(point) {
-  return Boolean(
-    point && Number.isInteger(point.line) && Number.isInteger(point.column)
-  )
-}
-
-/**
- * Convert a unist position to a language server protocol range.
- *
- * If no position is given, a range is returned  which represents the beginning
- * of the document.
- *
- * @param {UnistPosition|null|undefined} position
- * @returns {Range}
- */
-function unistLocationToLspRange(position) {
-  if (position) {
-    const end = isValidUnistPoint(position.end)
-      ? unistPointToLspPosition(position.end)
-      : undefined
-    const start = isValidUnistPoint(position.start)
-      ? unistPointToLspPosition(position.start)
-      : end
-
-    if (start) {
-      return Range.create(start, end || start)
-    }
-  }
-
-  return Range.create(0, 0, 0, 0)
-}
-
 /**
  * Convert a vfile message to a language server protocol diagnostic.
  *
@@ -106,7 +59,9 @@ function unistLocationToLspRange(position) {
  */
 function vfileMessageToDiagnostic(message) {
   const diagnostic = Diagnostic.create(
-    unistLocationToLspRange(message.position),
+    message.position
+      ? fromPosition(message.position)
+      : Range.create(0, 0, 0, 0),
     String(message.stack || message.reason),
     message.fatal === true
       ? DiagnosticSeverity.Error

package.json

@@ -33,10 +33,10 @@
     "index.d.ts"
   ],
   "dependencies": {
-    "@types/unist": "^2.0.0",
     "find-up": "^6.0.0",
     "load-plugin": "^5.0.0",
     "unified-engine": "^10.0.0",
+    "unist-util-lsp": "^1.0.0",
     "vfile": "^5.0.0",
     "vfile-message": "^3.0.0",
     "vscode-languageserver": "^8.0.0",