fix(graph): Support enclosing range for constructors (#372)

* Add supporting range support for the constructor

* revert mistakenly pushed file

* Add missing return type

* PR feedback and simplification

* update comment

Author: mmanela

.vscode/launch.json

@@ -0,0 +1,12 @@
+{
+  "version": "0.2.0",
+  "configurations": [
+    {
+      "type": "node",
+      "request": "launch",
+      "name": "Debug Tests",
+      "runtimeExecutable": "npm",
+      "runtimeArgs": ["run", "test"]
+    }
+  ]
+}

snapshots/output/enclosing-ranges/range.js

@@ -34,6 +34,7 @@ function test2() {
 // < start enclosing_range enclosing-ranges 0.0.1 `range.js`/Test#
 class Test {
 //    ^^^^ definition enclosing-ranges 0.0.1 `range.js`/Test#
+// ⌄ start enclosing_range enclosing-ranges 0.0.1 `range.js`/Test#`<constructor>`().
   constructor() {
 //^^^^^^^^^^^ definition enclosing-ranges 0.0.1 `range.js`/Test#`<constructor>`().
     const a = 'a'
@@ -45,6 +46,7 @@ class Test {
 //         ^ reference local 14
 //             ^ reference local 17
   }
+// ^ end enclosing_range enclosing-ranges 0.0.1 `range.js`/Test#`<constructor>`().
 
 // ⌄ start enclosing_range enclosing-ranges 0.0.1 `range.js`/Test#test().
   test() {

src/FileIndexer.ts

@@ -166,7 +166,13 @@ export class FileIndexer {
   }
 
   private visitSymbolOccurrence(node: ts.Node, sym: ts.Symbol): void {
-    const range = Range.fromNode(node).toLsif()
+    const isConstructor = ts.isConstructorDeclaration(node)
+    // For constructors, this method is passed the declaration node and not the identifier node.
+    // In either case, this method needs to get the range of the "name" of the declaration, for constructors we
+    // get the firstToken which contains the text "constructor".
+    const range = Range.fromNode(
+      isConstructor ? node.getFirstToken() ?? node : node
+    ).toLsif()
     let role = 0
     let declarations: ts.Node[] =
       this.getDeclarationsForPropertyAssignment(node) ?? []
@@ -207,7 +213,8 @@ export class FileIndexer {
         ts.isTypeAliasDeclaration(declaration) ||
         ts.isClassDeclaration(declaration) ||
         ts.isMethodDeclaration(declaration) ||
-        ts.isInterfaceDeclaration(declaration)
+        ts.isInterfaceDeclaration(declaration) ||
+        ts.isConstructorDeclaration(declaration)
       ) {
         enclosingRange = Range.fromNode(declaration).toLsif()
       }

src/Range.ts

@@ -33,18 +33,17 @@ export class Range {
       new Position(endLine, endCharacter)
     )
   }
+
   public static fromNode(node: ts.Node): Range {
     const sourceFile = node.getSourceFile()
-    const rangeNode: ts.Node = ts.isConstructorDeclaration(node)
-      ? node.getFirstToken() ?? node
-      : node
-    const start = sourceFile.getLineAndCharacterOfPosition(rangeNode.getStart())
-    const end = sourceFile.getLineAndCharacterOfPosition(rangeNode.getEnd())
+    const start = sourceFile.getLineAndCharacterOfPosition(node.getStart())
+    const end = sourceFile.getLineAndCharacterOfPosition(node.getEnd())
     return new Range(
       new Position(start.line, start.character),
       new Position(end.line, end.character)
     )
   }
+
   public isSingleLine(): boolean {
     return this.start.line === this.end.line
   }