Add functions to convert selection ranges (#2)

LSP selection ranges define their parent selection range using the
`parent` property. Monaco editor on the other hand, defines this
ancestry as an array. This means that a singular Monaco editor selection
range can’t be represented in LSP.

This deprecates the functions `fromSelectionRange` and
`toSelectionRange` in favor the plural variants `fromSelectionRanges`
and `toSelectionRanges`.

src/index.ts

@@ -35,6 +35,7 @@ export { fromPosition, toPosition } from './position.js'
 export { fromRange, toRange } from './range.js'
 export { fromRelatedInformation, toRelatedInformation } from './relatedInformation.js'
 export { fromSelectionRange, toSelectionRange } from './selectionRange.js'
+export { fromSelectionRanges, toSelectionRanges } from './selectionRanges.js'
 export { fromSemanticTokens, toSemanticTokens } from './semanticTokens.js'
 export { fromSemanticTokensEdit, toSemanticTokensEdit } from './semanticTokensEdit.js'
 export { fromSemanticTokensEdits, toSemanticTokensEdits } from './semanticTokensEdits.js'

src/selectionRange.ts

@@ -10,6 +10,8 @@ import { fromRange, toRange } from './range.js'
  *   The Monaco selection range to convert.
  * @returns
  *   The selection range as an LSP selection range.
+ * @deprecated
+ * Use `fromSelectionRanges` instead.
  */
 export function fromSelectionRange(
   selectionRange: monaco.languages.SelectionRange
@@ -26,6 +28,8 @@ export function fromSelectionRange(
  *   The LSP selection range to convert.
  * @returns
  *   The selection range as Monaco editor selection range.
+ * @deprecated
+ * Use `toSelectionRanges` instead.
  */
 export function toSelectionRange(
   selectionRange: lsp.SelectionRange

src/selectionRanges.ts

@@ -0,0 +1,56 @@
+import type * as monaco from 'monaco-types'
+import type * as lsp from 'vscode-languageserver-protocol'
+
+import { fromRange, toRange } from './range.js'
+
+/**
+ * Convert Monaco editor selection ranges to an LSP selection ranges.
+ *
+ * @param selectionRanges
+ *   The Monaco selections range to convert.
+ * @returns
+ *   The selection ranges as LSP selection range.
+ */
+export function fromSelectionRanges(
+  selectionRanges: monaco.languages.SelectionRange[]
+): lsp.SelectionRange | undefined {
+  let result: lsp.SelectionRange | undefined
+
+  for (let index = selectionRanges.length - 1; index >= 0; index -= 1) {
+    const parent = result
+
+    result = {
+      range: fromRange(selectionRanges[index].range)
+    }
+
+    if (parent) {
+      result.parent = parent
+    }
+  }
+
+  return result
+}
+
+/**
+ * Convert an LSP selection range to Monaco editor selection ranges.
+ *
+ * @param selectionRange
+ *   The LSP selection range to convert.
+ * @returns
+ *   The selection range as Monaco editor selection ranges.
+ */
+export function toSelectionRanges(
+  selectionRange: lsp.SelectionRange | undefined
+): monaco.languages.SelectionRange[] {
+  const result: monaco.languages.SelectionRange[] = []
+  let current = selectionRange
+
+  while (current) {
+    result.push({
+      range: toRange(current.range)
+    })
+    current = current.parent
+  }
+
+  return result
+}

test/selectionRanges.test.ts

@@ -0,0 +1,25 @@
+import { runTests } from './utils.js'
+import { fromSelectionRanges, toSelectionRanges } from '../src/index.js'
+
+runTests(fromSelectionRanges, toSelectionRanges)(
+  {
+    lsp: { range: { start: { line: 0, character: 0 }, end: { line: 0, character: 0 } } },
+    monaco: [{ range: { startLineNumber: 1, startColumn: 1, endLineNumber: 1, endColumn: 1 } }]
+  },
+  {
+    lsp: {
+      range: { start: { line: 0, character: 0 }, end: { line: 0, character: 0 } },
+      parent: {
+        range: { start: { line: 10, character: 10 }, end: { line: 10, character: 10 } },
+        parent: {
+          range: { start: { line: 20, character: 20 }, end: { line: 20, character: 20 } }
+        }
+      }
+    },
+    monaco: [
+      { range: { startLineNumber: 1, startColumn: 1, endLineNumber: 1, endColumn: 1 } },
+      { range: { startLineNumber: 11, startColumn: 11, endLineNumber: 11, endColumn: 11 } },
+      { range: { startLineNumber: 21, startColumn: 21, endLineNumber: 21, endColumn: 21 } }
+    ]
+  }
+)