Make hover work even if parsing fails

Author: skovhus

server/src/__tests__/server.test.ts

@@ -1046,8 +1046,22 @@ describe('server', () => {
         line: 2,
         character: 3,
       })
-      expect(result2).toBeDefined()
-      expect((result2 as any)?.contents.value).toBeUndefined()
+      expect(result2).toEqual(null)
+    })
+
+    it('responds with documentation even if parsing fails', async () => {
+      const result = await getHoverResult(FIXTURE_URI.MISSING_NODE2, {
+        // sleep
+        line: 12,
+        character: 4,
+      })
+
+      expect(result).toEqual({
+        contents: {
+          kind: 'markdown',
+          value: expect.stringContaining('suspends execution'),
+        },
+      })
     })
 
     it.skip('returns documentation from explainshell', async () => {

server/src/util/declarations.ts

@@ -154,20 +154,20 @@ export function getLocalDeclarations({
       node.type === 'program'
         ? node
         : TreeSitterUtil.findParent(node, (p) => p.type === 'program')
-    if (!rootNode) {
-      throw new Error('did not find root node')
-    }
 
-    Object.entries(
-      getAllGlobalVariableDeclarations({
-        rootNode,
-        uri,
-      }),
-    ).map(([name, symbols]) => {
-      if (!declarations[name]) {
-        declarations[name] = symbols
-      }
-    })
+    if (rootNode) {
+      // In case of parsing errors, the root node might not be found
+      Object.entries(
+        getAllGlobalVariableDeclarations({
+          rootNode,
+          uri,
+        }),
+      ).map(([name, symbols]) => {
+        if (!declarations[name]) {
+          declarations[name] = symbols
+        }
+      })
+    }
   }
 
   return declarations