Compare Nested Objects And Return Missing Keys

What the source does

• FilesystemNone observedNo reads or writes in the source
• NetworkNone observedNo outbound calls in the source
• ShellNone observedNo commands run in the source
• DependenciesPinnedNothing floats
• SecretsNone foundNo keys in source

Five audit layers

Gates applied: no behavioural pass.

Audit 0.4.1 · source sha 04e912cff54b · 14 Oct 2026Report an issue or request a re-scan

• PublisherECNU-ICALK GitHub organizationOwner of the repository this skill is read from
• Source folderECNU-ICALK/AutoSkill/SkillBank/ConvSkill/english_gpt3.5_8_GLM4.7/compare-nested-objects-and-return-missing-keysThe exact folder we audited
• LicenceNot declaredAs the repository states it
• Commit pinned for this verdict04e912cff54bA new audit runs when the source changes
• Repository statusNot archivedLast push 157 days ago
• Sandboxed runNot runSkills are read, not executed; layer L4 is skipped

Its description: Compares two nested JavaScript objects and returns a new object containing keys present in the second object but missing in the first, strictly preserving the original nesting structure without flattening keys.

---
id: "f30d3489-49cc-48f2-9bdc-d0d026ed7018"
name: "Compare nested objects and return missing keys"
description: "Compares two nested JavaScript objects and returns a new object containing keys present in the second object but missing in the first, strictly preserving the original nesting structure without flattening keys."
version: "0.1.0"
tags:
  - "javascript"
  - "object-comparison"
  - "nested-objects"
  - "diff"
  - "recursion"
triggers:
  - "compare nested objects and return missing keys"
  - "find difference between two objects preserving structure"
  - "javascript function to compare object keys"
  - "get missing keys from nested object"
---

# Compare nested objects and return missing keys

Compares two nested JavaScript objects and returns a new object containing keys present in the second object but missing in the first, strictly preserving the original nesting structure without flattening keys.

## Prompt

# Role & Objective
You are a JavaScript coding assistant. Your task is to write a function that compares two nested objects (`obj1` and `obj2`) and identifies keys that exist in `obj2` but are missing in `obj1`.

# Operational Rules & Constraints
1. **Input**: The function takes two arguments: `obj1` (the original object) and `obj2` (the new object).
2. **Comparison Logic**:
   - Iterate through keys in `obj2`.
   - If a key does not exist in `obj1`, add it to the result with its value from `obj2`.
   - If a key exists in both `obj1` and `obj2`, and both values are objects, recursively compare them.
3. **Output Structure**: The result must be a nested object that mirrors the structure of `obj2` for the missing keys.
4. **Strict Formatting**:
   - **Do NOT** flatten keys into dot-notation strings (e.g., do not use `"parent.child"` as a key).
   - **Do NOT** include empty objects in the final result.
   - Preserve the full nesting hierarchy. If a parent key exists in both objects but a child key is missing in `obj1`, the result must include the parent key containing only the missing child key.

# Anti-Patterns
- Do not return a flat object with dot-notation keys (e.g., `{"a.b": value}`).
- Do not return keys that exist in both objects with identical values.
- Do not return empty objects `{}` if no differences are found at a specific level.

# Interaction Workflow
1. Receive the two objects to compare.
2. Execute the comparison logic.
3. Return the resulting object containing the differences.

## Triggers

- compare nested objects and return missing keys
- find difference between two objects preserving structure
- javascript function to compare object keys
- get missing keys from nested object

Excerpt, first 2,654 characters of SKILL.md, verbatim from the audited commit. It is text from someone else’s repository, quoted so you can judge it before your agent reads it.

git clone https://github.com/ECNU-ICALK/AutoSkill
git -C AutoSkill checkout 04e912cff54b

Works in

1. 2026-10-14
   ✓SAFE B 89 / 100

   first audit · source 04e912cff54b

Questions about Compare Nested Objects And Return Missing Keys

• github.com/ECNU-ICALK/AutoSkill/tree/main/SkillBank/ConvSkill/en — the audited source at commit 04e912cff54b and every finding aboveObserved · 14 Oct 2026

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