Remove lodash and async dependencies to reduce bundle size by e-gineer · Pull Request #84 · turbot/sdk

e-gineer · 2026-01-09T04:39:29Z

Summary

Remove lodash (~25KB gzipped) and async (~8KB gzipped) dependencies
Replace with native JavaScript utility helpers
Remove eslint-plugin-you-dont-need-lodash-underscore dev dependency

Changes

Add utility helpers at top of index.js: get, defaults, omitNil, isEmpty, isPlainObject, deepMerge
Replace all lodash calls with native equivalents
Replace asyncjs.forever() with recursive setTimeout loop
Update test/sender.js to use setTimeout instead of _.delay()

Test plan

All 129 tests pass
No breaking changes to public API
Verified no remaining lodash/async imports

Closes #83

🤖 Generated with Claude Code

Replace lodash and async with native JavaScript equivalents: - Add utility helpers: get, defaults, omitNil, isEmpty, isPlainObject, deepMerge - Replace _.get(), _.defaults(), _.omitBy(), _.isEmpty(), _.isString(), _.isPlainObject(), _.isNil(), _.merge(), _.delay() with native alternatives - Replace asyncjs.forever() with recursive setTimeout loop - Remove eslint-plugin-you-dont-need-lodash-underscore This reduces Lambda bundle size by ~33KB (gzipped). Closes #83 Co-Authored-By: Claude Opus 4.5 <noreply@anthropic.com>

Copilot

Pull request overview

This pull request removes the lodash and async dependencies to reduce bundle size, replacing them with native JavaScript implementations. While the intent is sound, there are critical issues with the implementation that need to be addressed before merging.

Key Changes:

Added 6 utility helper functions (get, defaults, omitNil, isEmpty, isPlainObject, deepMerge) to replace lodash functionality
Replaced all lodash method calls with native equivalents or the new utility helpers
Replaced async.forever() with a recursive setTimeout loop pattern
Removed dependencies from package.json and package-lock.json
Removed eslint-plugin-you-dont-need-lodash-underscore and related ESLint configuration

Reviewed changes

Copilot reviewed 3 out of 4 changed files in this pull request and generated 6 comments.

File	Description
index.js	Added utility helpers and replaced all lodash/async usage with native equivalents
test/sender.js	Replaced `_.delay()` with `setTimeout()`
package.json	Removed async, lodash, and eslint plugin dependencies; updated ESLint configuration
package-lock.json	Removed dependency entries and transitive dependencies for async, lodash, and eslint plugin

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Copilot · 2026-01-09T05:54:30Z

+const deepMerge = (target, source) => {
+  const result = { ...target };
+  if (source && typeof source === "object" && !Array.isArray(source)) {
+    for (const key of Object.keys(source)) {
+      if (isPlainObject(source[key]) && isPlainObject(result[key])) {
+        result[key] = deepMerge(result[key], source[key]);
+      } else {
+        result[key] = source[key];
+      }
+    }
+  }
+  return result;
+};
+


The deepMerge utility function is defined but never used in the codebase. This appears to be dead code that should either be used to replace the Object.assign() calls where _.merge() was previously used, or removed if it's not needed.

Suggested change

const deepMerge = (target, source) => {

const result = { ...target };

if (source && typeof source === "object" && !Array.isArray(source)) {

for (const key of Object.keys(source)) {

if (isPlainObject(source[key]) && isPlainObject(result[key])) {

result[key] = deepMerge(result[key], source[key]);

} else {

result[key] = source[key];

}

}

}

return result;

};

Copilot · 2026-01-09T05:54:31Z

    };

-    _.merge(variables.input, turbotData);
+    Object.assign(variables.input, turbotData);


Replacing _.merge() with Object.assign() changes the merging behavior from deep merge to shallow merge. This is a breaking change that could cause issues if turbotData contains nested objects that should be deeply merged with variables.input. Consider using the deepMerge() utility function defined at the top of the file instead, or verify that shallow merging is the intended behavior for this specific use case.

Suggested change

Object.assign(variables.input, turbotData);

deepMerge(variables.input, turbotData);

Copilot · 2026-01-09T05:54:31Z

        };

-        _.merge(variables.input, turbotData);
+        Object.assign(variables.input, turbotData);


Replacing _.merge() with Object.assign() changes the merging behavior from deep merge to shallow merge. This is a breaking change that could cause issues if turbotData contains nested objects that should be deeply merged with variables.input. Consider using the deepMerge() utility function defined at the top of the file instead, or verify that shallow merging is the intended behavior for this specific use case.

Suggested change

Object.assign(variables.input, turbotData);

if (turbotData) {

variables.input = deepMerge(variables.input, turbotData);

}

Copilot · 2026-01-09T05:54:31Z

        };

-        _.merge(variables.input, turbotData);
+        Object.assign(variables.input, turbotData);


Replacing _.merge() with Object.assign() changes the merging behavior from deep merge to shallow merge. This is a breaking change that could cause issues if turbotData contains nested objects that should be deeply merged with variables.input. Consider using the deepMerge() utility function defined at the top of the file instead, or verify that shallow merging is the intended behavior for this specific use case.

Suggested change

Object.assign(variables.input, turbotData);

deepMerge(variables.input, turbotData);

Copilot · 2026-01-09T05:54:31Z

        };

-        _.merge(variables.input, turbotData);
+        Object.assign(variables.input, turbotData);


Replacing _.merge() with Object.assign() changes the merging behavior from deep merge to shallow merge. This is a breaking change that could cause issues if turbotData contains nested objects that should be deeply merged with variables.input. Consider using the deepMerge() utility function defined at the top of the file instead, or verify that shallow merging is the intended behavior for this specific use case.

Suggested change

Object.assign(variables.input, turbotData);

deepMerge(variables.input, turbotData);

Copilot · 2026-01-09T05:54:32Z

 const { v4: uuidv4 } = require("uuid");

+// Utility helpers (replacing lodash)
+const isPlainObject = (val) => typeof val === "object" && val !== null && val.constructor === Object;


The isPlainObject implementation may not handle edge cases correctly. Objects created with Object.create(null) don't have a constructor property and would throw an error when accessing val.constructor. Consider adding a check: val.constructor === Object || Object.getPrototypeOf(val) === null.

Suggested change

const isPlainObject = (val) => typeof val === "object" && val !== null && val.constructor === Object;

const isPlainObject = (val) =>

typeof val === "object" &&

val !== null &&

(val.constructor === Object || Object.getPrototypeOf(val) === null);

vhadianto · 2026-01-09T06:13:53Z

I've asked Claude to check _.merge vs Object.assign vs deepMerge function:

const _ = require("lodash");

// Helper function to check if value is plain object
const isPlainObject = (obj) => {
  return Object.prototype.toString.call(obj) === "[object Object]";
};

// Custom deepMerge implementation (from the user)
const deepMerge = (target, source) => {
  const result = { ...target };
  if (source && typeof source === "object" && !Array.isArray(source)) {
    for (const key of Object.keys(source)) {
      if (isPlainObject(source[key]) && isPlainObject(result[key])) {
        result[key] = deepMerge(result[key], source[key]);
      } else {
        result[key] = source[key];
      }
    }
  }
  return result;
};

// Test cases
console.log("=" .repeat(80));
console.log("MERGE COMPARISON TESTS");
console.log("=" .repeat(80));

// Test 1: Simple nested objects
console.log("\n1. NESTED OBJECTS TEST");
console.log("-".repeat(80));
const target1 = {
  a: 1,
  b: {
    c: 2,
    d: 3,
  },
};
const source1 = {
  b: {
    d: 4,
    e: 5,
  },
  f: 6,
};

console.log("Target:", JSON.stringify(target1, null, 2));
console.log("Source:", JSON.stringify(source1, null, 2));

const assignResult1 = Object.assign({}, target1, source1);
const lodashResult1 = _.merge({}, target1, source1);
const deepMergeResult1 = deepMerge(target1, source1);

console.log("\nObject.assign result:", JSON.stringify(assignResult1, null, 2));
console.log("Expected: b.c is LOST (shallow copy replaces entire b object)");

console.log("\nlodash.merge result:", JSON.stringify(lodashResult1, null, 2));
console.log("Expected: b.c is PRESERVED (deep merge)");

console.log("\nCustom deepMerge result:", JSON.stringify(deepMergeResult1, null, 2));
console.log("Expected: b.c is PRESERVED (deep merge)");

// Test 2: Array handling
console.log("\n\n2. ARRAY HANDLING TEST");
console.log("-".repeat(80));
const target2 = {
  items: [1, 2, 3],
  nested: {
    arr: ["a", "b"],
  },
};
const source2 = {
  items: [4, 5],
  nested: {
    arr: ["c"],
  },
};

console.log("Target:", JSON.stringify(target2, null, 2));
console.log("Source:", JSON.stringify(source2, null, 2));

const assignResult2 = Object.assign({}, target2, source2);
const lodashResult2 = _.merge({}, target2, source2);
const deepMergeResult2 = deepMerge(target2, source2);

console.log("\nObject.assign result:", JSON.stringify(assignResult2, null, 2));
console.log("Expected: items = [4, 5] (array replaced)");

console.log("\nlodash.merge result:", JSON.stringify(lodashResult2, null, 2));
console.log("Expected: items = [4, 5, 3] (arrays merged by index!)");

console.log("\nCustom deepMerge result:", JSON.stringify(deepMergeResult2, null, 2));
console.log("Expected: items = [4, 5] (array replaced)");

// Test 3: Multiple levels deep
console.log("\n\n3. DEEP NESTING TEST");
console.log("-".repeat(80));
const target3 = {
  level1: {
    level2: {
      level3: {
        value: "original",
        keep: "this",
      },
    },
  },
};
const source3 = {
  level1: {
    level2: {
      level3: {
        value: "updated",
      },
    },
  },
};

console.log("Target:", JSON.stringify(target3, null, 2));
console.log("Source:", JSON.stringify(source3, null, 2));

const assignResult3 = Object.assign({}, target3, source3);
const lodashResult3 = _.merge({}, target3, source3);
const deepMergeResult3 = deepMerge(target3, source3);

console.log("\nObject.assign result:", JSON.stringify(assignResult3, null, 2));
console.log("Expected: level1.level2.level3.keep is LOST");

console.log("\nlodash.merge result:", JSON.stringify(lodashResult3, null, 2));
console.log("Expected: level1.level2.level3.keep is PRESERVED");

console.log("\nCustom deepMerge result:", JSON.stringify(deepMergeResult3, null, 2));
console.log("Expected: level1.level2.level3.keep is PRESERVED");

// Test 4: Mutation test
console.log("\n\n4. MUTATION TEST (Does it modify original objects?)");
console.log("-".repeat(80));
const target4 = { a: 1, b: { c: 2 } };
const source4 = { b: { d: 3 } };

console.log("Before merge:");
console.log("Target:", JSON.stringify(target4, null, 2));
console.log("Source:", JSON.stringify(source4, null, 2));

// Test Object.assign
const target4a = JSON.parse(JSON.stringify(target4)); // Deep clone for test
const source4a = JSON.parse(JSON.stringify(source4));
Object.assign({}, target4a, source4a);
console.log("\nAfter Object.assign:");
console.log("Target modified?", JSON.stringify(target4a) !== JSON.stringify(target4));
console.log("Source modified?", JSON.stringify(source4a) !== JSON.stringify(source4));

// Test lodash.merge (NOTE: _.merge MUTATES the first argument!)
const target4b = JSON.parse(JSON.stringify(target4));
const source4b = JSON.parse(JSON.stringify(source4));
_.merge({}, target4b, source4b); // Using {} as first arg prevents mutation
console.log("\nAfter lodash.merge (with {} as first arg):");
console.log("Target modified?", JSON.stringify(target4b) !== JSON.stringify(target4));
console.log("Source modified?", JSON.stringify(source4b) !== JSON.stringify(source4));

// Test lodash.merge WITHOUT empty object first
const target4c = JSON.parse(JSON.stringify(target4));
const source4c = JSON.parse(JSON.stringify(source4));
_.merge(target4c, source4c); // MUTATES target4c
console.log("\nAfter lodash.merge (WITHOUT {} as first arg):");
console.log("Target modified?", JSON.stringify(target4c) !== JSON.stringify(target4), "- TARGET WAS MUTATED!");

// Test custom deepMerge
const target4d = JSON.parse(JSON.stringify(target4));
const source4d = JSON.parse(JSON.stringify(source4));
deepMerge(target4d, source4d);
console.log("\nAfter custom deepMerge:");
console.log("Target modified?", JSON.stringify(target4d) !== JSON.stringify(target4));
console.log("Source modified?", JSON.stringify(source4d) !== JSON.stringify(source4));

// Test 5: Undefined and null handling
console.log("\n\n5. UNDEFINED AND NULL HANDLING");
console.log("-".repeat(80));
const target5 = { a: 1, b: 2, c: 3 };
const source5 = { b: undefined, c: null, d: 4 };

console.log("Target:", JSON.stringify(target5, null, 2));
console.log("Source:", JSON.stringify(source5, null, 2));

const assignResult5 = Object.assign({}, target5, source5);
const lodashResult5 = _.merge({}, target5, source5);
const deepMergeResult5 = deepMerge(target5, source5);

console.log("\nObject.assign result:", JSON.stringify(assignResult5, null, 2));
console.log("\nlodash.merge result:", JSON.stringify(lodashResult5, null, 2));
console.log("Note: lodash.merge SKIPS undefined values!");
console.log("\nCustom deepMerge result:", JSON.stringify(deepMergeResult5, null, 2));

// Test 6: Performance comparison
console.log("\n\n6. PERFORMANCE TEST");
console.log("-".repeat(80));
const iterations = 100000;

// Create test objects
const perfTarget = {
  a: 1,
  b: { c: 2, d: { e: 3, f: 4 } },
  g: [1, 2, 3],
  h: "string",
};
const perfSource = {
  b: { d: { f: 5, g: 6 } },
  g: [4, 5],
  i: "new",
};

// Test Object.assign
console.time("Object.assign");
for (let i = 0; i < iterations; i++) {
  Object.assign({}, perfTarget, perfSource);
}
console.timeEnd("Object.assign");

// Test lodash.merge
console.time("lodash.merge");
for (let i = 0; i < iterations; i++) {
  _.merge({}, perfTarget, perfSource);
}
console.timeEnd("lodash.merge");

// Test custom deepMerge
console.time("custom deepMerge");
for (let i = 0; i < iterations; i++) {
  deepMerge(perfTarget, perfSource);
}
console.timeEnd("custom deepMerge");

Summary:

================================================================================
SUMMARY AND RECOMMENDATIONS
================================================================================

Key Differences:

1. OBJECT.ASSIGN (Shallow Copy):
   - ✗ Only copies top-level properties
   - ✗ Nested objects are REPLACED, not merged
   - ✗ Original nested data is LOST
   - ✓ Fastest performance
   - ✓ Does not mutate (when used with {})

2. LODASH.MERGE (Deep Merge):
   - ✓ Recursively merges nested objects
   - ✓ Preserves nested data
   - ✗ MUTATES first argument if not using {}
   - ✗ Arrays are merged by INDEX (unusual behavior!)
   - ✗ Skips undefined values
   - ✗ Slower performance

3. CUSTOM DEEPMERGE (Deep Merge):
   - ✓ Recursively merges nested objects
   - ✓ Preserves nested data
   - ✓ Does not mutate (creates new objects)
   - ✓ Arrays are REPLACED (more intuitive)
   - ✓ Handles undefined/null consistently
   - ✓ Medium performance (between Object.assign and lodash)

vhadianto · 2026-01-09T07:47:14Z

I think given that Object.assign is shallow copy, custom deepMerge function is better.

However from the above test, there are 2 risks:

LODASH.MERGE (Deep Merge):
- ✗ Arrays are merged by INDEX (unusual behavior!)
- ✗ Skips undefined values
CUSTOM DEEPMERGE (Deep Merge):
- ✓ Arrays are REPLACED (more intuitive)
- ✓ Handles undefined/null consistently

The Array handling could be a problem. This is the result of the Array handling test between the two:

2. ARRAY HANDLING TEST
--------------------------------------------------------------------------------
Target: {
  "items": [
    1,
    2,
    3
  ],
  "nested": {
    "arr": [
      "a",
      "b"
    ]
  }
}
Source: {
  "items": [
    4,
    5
  ],
  "nested": {
    "arr": [
      "c"
    ]
  }
}

Object.assign result: {
  "items": [
    4,
    5
  ],
  "nested": {
    "arr": [
      "c"
    ]
  }
}
Expected: items = [4, 5] (array replaced)

lodash.merge result: {
  "items": [
    4,
    5,
    3
  ],
  "nested": {
    "arr": [
      "c",
      "b"
    ]
  }
}
Expected: items = [4, 5, 3] (arrays merged by index!)

Custom deepMerge result: {
  "items": [
    4,
    5
  ],
  "nested": {
    "arr": [
      "c"
    ]
  }
}
Expected: items = [4, 5] (array replaced)

vhadianto requested a review from Copilot January 9, 2026 05:51

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Remove lodash and async dependencies to reduce bundle size#84

Remove lodash and async dependencies to reduce bundle size#84
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	Object.assign(variables.input, turbotData);
	deepMerge(variables.input, turbotData);

-        Object.assign(variables.input, turbotData);
+        if (turbotData) {
+          variables.input = deepMerge(variables.input, turbotData);
+        }

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