Adds bailing heuristic for symbol table calc + test

packages/language-server/package.json

@@ -50,7 +50,8 @@
     "bundle": "esbuild ./src/server.ts --bundle --format=cjs --platform=node --outfile=dist/cypher-language-server.js --minify --conditions=require",
     "dev": "tsc --watch",
     "make-executable": "cd dist && echo '#!/usr/bin/env node' > cypher-language-server && cat cypher-language-server.js >> cypher-language-server",
-    "clean": "rm -rf {dist,tsconfig.tsbuildinfo}"
+    "clean": "rm -rf {dist,tsconfig.tsbuildinfo}",
+    "test": "vitest run"
   },
   "devDependencies": {
     "@types/lodash.debounce": "^4.0.9",

packages/language-server/src/helpers.ts

@@ -0,0 +1,32 @@
+/**Checks if we should bail on the job, which would be if we have only typed a letter/number/underscore */
+export function shouldBail(query: string, oldQuery: string) {
+  //Trying to determine if we typed in a single character or copy-pasted, and if single char, if this new char is a non number/letter
+
+  let shouldBail = false;
+  if (query.length === oldQuery.length + 1) {
+    let newCharCandidateIndex: number = undefined;
+    for (let i = 0; i < oldQuery.length; i++) {
+      //if we just consider typing, we only have 1 diff, the inserted symbol
+      //if diff, the symbol was inserted into newquery here, if we never do the new symbol is the last
+      //if we copypaste, we could do to equally long -> in that case, removing the first diff symbol would not yield
+      //the same query
+      if (query[i] != oldQuery[i]) {
+        newCharCandidateIndex = i;
+        break;
+      }
+    }
+    newCharCandidateIndex = newCharCandidateIndex ?? query.length - 1;
+    const oldifiedNewQuery =
+      query.slice(0, newCharCandidateIndex) +
+      query.slice(newCharCandidateIndex + 1, query.length);
+    if (oldifiedNewQuery === oldQuery) {
+      const newChar = query[newCharCandidateIndex];
+      const letterOrNumber = /^\w/;
+      const isLetterOrNumber = newChar.match(letterOrNumber);
+      if (isLetterOrNumber) {
+        shouldBail = true;
+      }
+    }
+  }
+  return shouldBail;
+}

packages/language-server/src/server.ts

@@ -32,6 +32,7 @@ import {
 import workerpool from 'workerpool';
 import { join } from 'path';
 import { LintWorker } from '@neo4j-cypher/lint-worker';
+import { shouldBail } from './helpers';
 
 class SymbolFetcher {
   private processing = false;
@@ -45,8 +46,15 @@ class SymbolFetcher {
     maxWorkers: 1,
     workerTerminateTimeout: 0,
   });
+  private lastQuery: string = '';
 
   public queueSymbolJob(query: string, uri: string, schema: DbSchema) {
+    const bailEarly = shouldBail(query, this.lastQuery);
+    this.lastQuery = query;
+    if (bailEarly) {
+      return;
+    }
+
     this.nextJob = { query, uri, schema };
     if (!this.processing) {
       void this.processJobQueue();

packages/language-server/src/tests/misc.test.ts

@@ -0,0 +1,47 @@
+import { shouldBail } from '../helpers';
+
+const bailingCases = [
+  {
+    name: 'Typing letters in end',
+    lastQuery: 'MATCH (m',
+    nextQuery: 'MATCH (mn',
+    shouldBail: true,
+  },
+  {
+    name: 'Typing symbol in end',
+    lastQuery: 'MATCH (mnm',
+    nextQuery: 'MATCH (mnm:',
+    shouldBail: false,
+  },
+  //Here we would prefer to update the symbol table, but this heuristic would skip it (staying at "mn:Node" even after we rename to "mnm")
+  {
+    name: 'Typing letters in middle',
+    lastQuery: 'MATCH (mn)-[:',
+    nextQuery: 'MATCH (mnm)-[:',
+    shouldBail: true,
+  },
+  {
+    name: 'Typing symbol in middle',
+    lastQuery: 'MATCH (mnm)-[:',
+    nextQuery: 'MATCH (mnm )-[:',
+    shouldBail: false,
+  },
+  {
+    name: 'Pasting in multiple symbols at once',
+    lastQuery: 'RETURN 50',
+    nextQuery: 'MATCH (n) RETURN n',
+    shouldBail: false,
+  },
+];
+
+describe('Misc tests for the language server', () => {
+  test('Bailing logic for symbol table calculation', () => {
+    bailingCases.forEach((c) => {
+      expect(
+        shouldBail(c.nextQuery, c.lastQuery),
+        "Failed on test '" + c.name + "'",
+      ).toBe(c.shouldBail);
+    });
+    //expect(false).toBe(true);
+  });
+});

packages/language-server/tsconfig.json

@@ -2,7 +2,8 @@
   "extends": "../../tsconfig.base.json",
   "compilerOptions": {
     "outDir": "dist",
-    "rootDir": "src"
+    "rootDir": "src",
+    "types": ["vitest/globals"]
   },
   "include": ["src"]
 }

packages/language-server/tsconfig.node.json

@@ -0,0 +1,7 @@
+{
+  "extends": "../../tsconfig.base.json",
+  "include": ["vitest.config.mts"],
+  "compilerOptions": {
+    "noEmit": true
+  }
+}

packages/language-server/vitest.config.mts

@@ -0,0 +1,7 @@
+import { defineConfig } from 'vitest/config';
+
+export default defineConfig({
+  test: {
+    globals: true,
+  },
+});