Clear expect rule program cache when heap is almost exhausted (#1024)

* Clear expect rule program cache when heap is almost exhausted

* Update packages/eslint-plugin/src/rules/expect.ts

Co-authored-by: Jake Bailey <5341706+jakebailey@users.noreply.github.com>

* Clear expect rule program cache when heap is almost exhausted

---------

Co-authored-by: Jake Bailey <5341706+jakebailey@users.noreply.github.com>

.changeset/three-vans-fetch.md

@@ -0,0 +1,5 @@
+---
+"@definitelytyped/eslint-plugin": patch
+---
+
+Clear expect rule program cache when heap is almost exhausted

packages/eslint-plugin/src/rules/expect.ts

@@ -1,10 +1,11 @@
-import { createRule, findTypesPackage, findUp } from "../util";
 import { ESLintUtils, TSESTree } from "@typescript-eslint/utils";
-import type * as ts from "typescript";
-import path from "path";
-import fs from "fs";
 import { ReportDescriptorMessageData } from "@typescript-eslint/utils/ts-eslint";
+import fs from "fs";
+import v8 from "node:v8";
+import path from "path";
 import * as semver from "semver";
+import type * as ts from "typescript";
+import { createRule, findTypesPackage, findUp } from "../util";
 
 type TSModule = typeof ts;
 
@@ -198,6 +199,13 @@ function getProgram(
     newProgram = createProgram(path.resolve(dirPath, configFile), ts);
     versionToProgram.set(cacheKey, newProgram);
   }
+
+  const heapStats = v8.getHeapStatistics();
+  const heapUsage = heapStats.used_heap_size / heapStats.heap_size_limit;
+  if (heapUsage > 0.9) {
+    versionToProgram.clear();
+  }
+
   return newProgram;
 }