fix: enhance OAuth session handling and add tests for state resets

tests/background-cpa-state-plumbing.test.js

@@ -2,6 +2,54 @@ const test = require('node:test');
 const assert = require('node:assert/strict');
 const fs = require('node:fs');
 
+function extractFunction(source, name) {
+  const markers = [`async function ${name}(`, `function ${name}(`];
+  const start = markers
+    .map((marker) => source.indexOf(marker))
+    .find((index) => index >= 0);
+  if (start < 0) {
+    throw new Error(`missing function ${name}`);
+  }
+
+  let parenDepth = 0;
+  let signatureEnded = false;
+  let braceStart = -1;
+  for (let i = start; i < source.length; i += 1) {
+    const ch = source[i];
+    if (ch === '(') {
+      parenDepth += 1;
+    } else if (ch === ')') {
+      parenDepth -= 1;
+      if (parenDepth === 0) {
+        signatureEnded = true;
+      }
+    } else if (ch === '{' && signatureEnded) {
+      braceStart = i;
+      break;
+    }
+  }
+
+  if (braceStart < 0) {
+    throw new Error(`missing body for function ${name}`);
+  }
+
+  let depth = 0;
+  let end = braceStart;
+  for (; end < source.length; end += 1) {
+    const ch = source[end];
+    if (ch === '{') depth += 1;
+    if (ch === '}') {
+      depth -= 1;
+      if (depth === 0) {
+        end += 1;
+        break;
+      }
+    }
+  }
+
+  return source.slice(start, end);
+}
+
 test('background step-1 state plumbing persists and resets cpa oauth runtime keys', () => {
   const source = fs.readFileSync('background.js', 'utf8');
 
@@ -9,7 +57,17 @@ test('background step-1 state plumbing persists and resets cpa oauth runtime key
   assert.match(source, /cpaManagementOrigin:\s*null/);
   assert.match(source, /payload\.cpaOAuthState[^\n]*updates\.cpaOAuthState/);
   assert.match(source, /payload\.cpaManagementOrigin[^\n]*updates\.cpaManagementOrigin/);
-  assert.match(source, /if \(step <= 1\) \{[\s\S]*cpaOAuthState:\s*null,[\s\S]*cpaManagementOrigin:\s*null,/);
+
+  const harness = new Function(`
+function getStepExecutionKeyForState() {
+  return '';
+}
+${extractFunction(source, 'getDownstreamStateResets')}
+return { getDownstreamStateResets };
+`)();
+  const resets = harness.getDownstreamStateResets(1, {});
+  assert.equal(resets.cpaOAuthState, null);
+  assert.equal(resets.cpaManagementOrigin, null);
 });
 
 test('message router step-1 handler stores cpa oauth runtime keys', async () => {