fix: add deep equality check and update query matching

Author: hexqi

mockServer/src/store/FileStore.js

@@ -174,24 +174,64 @@ class FileStore extends StoreAdapter {
   }
 
   /**
-   * Check if a document matches the query
+   * Deep equality, mirroring NeDB's areThingsEqual: primitives by ===, Dates by
+   * timestamp, arrays and plain objects by recursive value comparison. An array
+   * never equals a non-array.
+   */
+  deepEqual(a, b) {
+    if (a === b) return true
+    if (a === null || b === null || typeof a !== 'object' || typeof b !== 'object') return false
+
+    const aIsArray = Array.isArray(a)
+    const bIsArray = Array.isArray(b)
+    if (aIsArray !== bIsArray) return false
+
+    if (a instanceof Date || b instanceof Date) {
+      return a instanceof Date && b instanceof Date && a.getTime() === b.getTime()
+    }
+
+    const aKeys = Object.keys(a)
+    const bKeys = Object.keys(b)
+    if (aKeys.length !== bKeys.length) return false
+    for (const k of aKeys) {
+      if (!Object.prototype.hasOwnProperty.call(b, k)) return false
+      if (!this.deepEqual(a[k], b[k])) return false
+    }
+    return true
+  }
+
+  /**
+   * Check if a document matches the query (NeDB-compatible semantics).
+   * An object query value is treated as an operator object only when every key
+   * starts with `$`; otherwise (plain object or array) it is deep-compared, so
+   * `{ config: { mode: 'x' } }` or `{ tags: ['a'] }` does not silently match all
+   * records. A RegExp query value is matched like `$regex`.
    */
   matchesQuery(doc, query) {
     if (!query || Object.keys(query).length === 0) {
       return true
     }
 
     for (const [key, value] of Object.entries(query)) {
-      if (typeof value === 'object' && value !== null) {
-        if (value.$regex && !value.$regex.test(doc[key])) return false
-        if (value.$ne !== undefined && doc[key] === value.$ne) return false
-        if (value.$in !== undefined && !value.$in.includes(doc[key])) return false
-        if (value.$nin !== undefined && value.$nin.includes(doc[key])) return false
-        if (value.$gt !== undefined && !(doc[key] > value.$gt)) return false
-        if (value.$gte !== undefined && !(doc[key] >= value.$gte)) return false
-        if (value.$lt !== undefined && !(doc[key] < value.$lt)) return false
-        if (value.$lte !== undefined && !(doc[key] <= value.$lte)) return false
-
+      if (value !== null && typeof value === 'object' && !(value instanceof RegExp)) {
+        const keys = Object.keys(value)
+        const isOperatorObject = keys.length > 0 && keys.every((k) => k.startsWith('$'))
+
+        if (isOperatorObject) {
+          if (value.$regex && !value.$regex.test(doc[key])) return false
+          if (value.$ne !== undefined && doc[key] === value.$ne) return false
+          if (value.$in !== undefined && !value.$in.includes(doc[key])) return false
+          if (value.$nin !== undefined && value.$nin.includes(doc[key])) return false
+          if (value.$gt !== undefined && !(doc[key] > value.$gt)) return false
+          if (value.$gte !== undefined && !(doc[key] >= value.$gte)) return false
+          if (value.$lt !== undefined && !(doc[key] < value.$lt)) return false
+          if (value.$lte !== undefined && !(doc[key] <= value.$lte)) return false
+        } else if (!this.deepEqual(doc[key], value)) {
+          // Plain object or array query value: deep-compare (NeDB areThingsEqual)
+          return false
+        }
+      } else if (value instanceof RegExp) {
+        if (!value.test(doc[key])) return false
       } else if (doc[key] !== value) {
         // Simple equality check
         return false

mockServer/test/store/adapter.contract.test.js

@@ -131,4 +131,28 @@ describe.each(adapterFactories)('%s honours the StoreAdapter contract', (_name,
     expect(await store.find({ _id: { $nin: ['p1'] } })).toHaveLength(2)
     expect(await store.find({ name: { $regex: /^ba/ } })).toHaveLength(2)
   })
+
+  test('plain object query value deep-compares instead of matching all', async () => {
+    await store.insert({ _id: 'o1', config: { mode: 'x', n: 1 } })
+    await store.insert({ _id: 'o2', config: { mode: 'y', n: 2 } })
+    await store.insert({ _id: 'o3', config: { mode: 'x', n: 3 } })
+
+    const matches = await store.find({ config: { mode: 'x', n: 1 } })
+    expect(matches).toHaveLength(1)
+    expect(matches[0]._id).toBe('o1')
+
+    // a plain object that matches no record must return none — not everything
+    expect(await store.find({ config: { mode: 'z' } })).toHaveLength(0)
+  })
+
+  test('array query value deep-compares instead of matching all', async () => {
+    await store.insert({ _id: 'a1', tags: ['red', 'blue'] })
+    await store.insert({ _id: 'a2', tags: ['green'] })
+
+    const matches = await store.find({ tags: ['red', 'blue'] })
+    expect(matches).toHaveLength(1)
+    expect(matches[0]._id).toBe('a1')
+
+    expect(await store.find({ tags: ['purple'] })).toHaveLength(0)
+  })
 })