Add code folding on single line comment

src/features/foldingProvider.ts

@@ -99,16 +99,48 @@ export default class AsciidocFoldingRangeProvider implements vscode.FoldingRange
     }
   }
 
+  private static handleSingleLineCommentFoldingRanges (singleLineCommentStartIndexes: any[], foldingRanges: any[], lineIndex: number, lineText: string,
+    documentLineCount: number) {
+    if (lineText.startsWith('//')) {
+      if (singleLineCommentStartIndexes.length === 0 && lineIndex < documentLineCount - 1) {
+        singleLineCommentStartIndexes.push(lineIndex)
+      } else {
+        // comment on last line of the document
+        const startIndex = singleLineCommentStartIndexes.pop()
+        if (lineIndex > startIndex) {
+          foldingRanges.push(new vscode.FoldingRange(
+            startIndex,
+            lineIndex,
+            FoldingRangeKind.Region)
+          )
+        }
+      }
+    } else {
+      if (singleLineCommentStartIndexes.length !== 0) {
+        const startIndex = singleLineCommentStartIndexes.pop()
+        const endIndex = lineIndex - 1
+        if (endIndex > startIndex) {
+          foldingRanges.push(new vscode.FoldingRange(
+            startIndex,
+            endIndex,
+            FoldingRangeKind.Region))
+        }
+      }
+    }
+  }
+
   private static getBlockFoldingRanges (document: vscode.TextDocument) {
     const foldingRanges = []
     const openBlockIndexes = []
     const commentBlockIndexes = []
+    const singleLineCommentStartIndexes = []
     const documentLineCount = document.lineCount
     for (let lineIndex = 0; lineIndex < documentLineCount; lineIndex++) {
       const line = document.lineAt(lineIndex)
       const lineText = line.text
       this.handleOpenBlockFoldingRanges(openBlockIndexes, foldingRanges, lineIndex, lineText, documentLineCount)
       this.handleCommentBlockFoldingRanges(commentBlockIndexes, foldingRanges, lineIndex, lineText, documentLineCount)
+      this.handleSingleLineCommentFoldingRanges(singleLineCommentStartIndexes, foldingRanges, lineIndex, lineText, documentLineCount)
     }
     return foldingRanges
   }

src/test/foldingProvider.test.ts

@@ -345,6 +345,56 @@ this is the same paragraph`)
       assert.strictEqual(folds.length, 0, 'expecting 0 fold')
     })
   })
+
+  suite('getSingleLineCommentFoldingRanges', () => {
+    test('Should fold on a group of single line comments ', () => {
+      const folds = getFoldsForDocument(
+        `this is a paragraph
+
+// A single-line comment.
+// Another single-line comment.
+
+this is a paragraph`)
+      assert.strictEqual(folds.length, 1, 'expecting 1 fold')
+      assert.deepStrictEqual(folds, [
+        new vscode.FoldingRange(2, 3, vscode.FoldingRangeKind.Region),
+      ])
+    })
+
+    test('Should not fold single line comment if not contiguous ', () => {
+      const folds = getFoldsForDocument(
+        `// A single-line comment.
+
+// Another single-line comment.
+
+// This is a comment too.
+
+This is a paragraph.
+
+// This is another comment.`)
+      assert.strictEqual(folds.length, 0, 'expecting 0 fold')
+    })
+
+    test('Should not fold single lines comments if slashes are part of literal text ', () => {
+      const folds = getFoldsForDocument(
+        `this is a paragraph
+ // This is literal text
+// This is a single line comment
+this is the same paragraph`)
+      assert.strictEqual(folds.length, 0, 'expecting 0 fold')
+    })
+
+    test('Should fold if last single line comment is on the last line of the document', () => {
+      const folds = getFoldsForDocument(
+        `this is a paragraph
+// This is a comment.
+// The last line of the document is also a comment!`)
+      assert.strictEqual(folds.length, 1, 'expecting 1 fold')
+      assert.deepStrictEqual(folds, [
+        new vscode.FoldingRange(1, 2, vscode.FoldingRangeKind.Region),
+      ])
+    })
+  })
 })
 
 function getFoldsForDocument (contents: string) {