Resurrect diagnostics for missing nodes

This seems useful, even though tree sitter usually do not
report these in more complicated docs.

Author: skovhus

server/src/__tests__/analyzer.test.ts

@@ -46,12 +46,30 @@ describe('analyze', () => {
     expect(loggerWarn).not.toHaveBeenCalled()
   })
 
-  it('parses files with a missing node', () => {
+  it('parses files with a missing nodes and return relevant diagnostics', () => {
     const diagnostics = analyzer.analyze({
       uri: CURRENT_URI,
       document: FIXTURE_DOCUMENT.MISSING_NODE,
     })
-    expect(diagnostics).toEqual([])
+    expect(diagnostics).toMatchInlineSnapshot(`
+      Array [
+        Object {
+          "message": "Syntax error: \\"fi\\" missing",
+          "range": Object {
+            "end": Object {
+              "character": 0,
+              "line": 12,
+            },
+            "start": Object {
+              "character": 0,
+              "line": 12,
+            },
+          },
+          "severity": 2,
+          "source": "bash-language-server",
+        },
+      ]
+    `)
     expect(loggerWarn).toHaveBeenCalledWith(
       'Error while parsing dummy-uri.sh: syntax error',
     )

server/src/analyser.ts

@@ -116,7 +116,11 @@ export default class Analyzer {
       logger.warn(`Error while parsing ${uri}: syntax error`)
     }
 
-    return diagnostics
+    const missingNodesDiagnostics = TreeSitterUtil.getDiagnosticsForMissingNodes(
+      tree.rootNode,
+    )
+
+    return diagnostics.concat(missingNodesDiagnostics)
   }
 
   /**

server/src/util/tree-sitter.ts

@@ -1,4 +1,4 @@
-import { Range } from 'vscode-languageserver/node'
+import { Diagnostic, DiagnosticSeverity, Range } from 'vscode-languageserver/node'
 import { SyntaxNode } from 'web-tree-sitter'
 
 /**
@@ -56,3 +56,24 @@ export function findParent(
   }
   return null
 }
+
+export function getDiagnosticsForMissingNodes(node: SyntaxNode) {
+  const diagnostics: Diagnostic[] = []
+
+  forEach(node, (node) => {
+    if (node.isMissing()) {
+      diagnostics.push(
+        Diagnostic.create(
+          range(node),
+          `Syntax error: "${node.type}" missing`,
+          DiagnosticSeverity.Warning,
+          undefined,
+          'bash-language-server',
+        ),
+      )
+    }
+    return node.hasError()
+  })
+
+  return diagnostics
+}