TL;DR: A Compilation of bad smells in code.

The code smells badly.

Let's see how to change the aromas.

In this series, we will see several symptoms and situations that make us doubt the quality of our development. We will present possible solutions.

Most of these smells are just hints of something that might be wrong. They are not rigid rules.

Code Smells

https://maximilianocontieri.com/code-smell-01-anemic-models

https://maximilianocontieri.com/code-smell-02-constants-and-magic-numbers

https://maximilianocontieri.com/code-smell-03-functions-are-too-long

https://maximilianocontieri.com/code-smell-04-string-abusers

https://maximilianocontieri.com/code-smell-05-comment-abusers

https://maximilianocontieri.com/code-smell-06-too-clever-programmer

https://maximilianocontieri.com/code-smell-07-boolean-variables

https://maximilianocontieri.com/code-smell-08-long-chains-of-collaborations

https://maximilianocontieri.com/code-smell-09-dead-code

https://maximilianocontieri.com/code-smell-10-too-many-arguments

https://maximilianocontieri.com/code-smell-11-subclassification-for-code-reuse

https://maximilianocontieri.com/code-smell-12-null

https://maximilianocontieri.com/code-smell-13-empty-constructors

https://maximilianocontieri.com/code-smell-14-god-objects

https://maximilianocontieri.com/code-smell-15-missed-preconditions-1

https://maximilianocontieri.com/code-smell-16-ripple-effect

https://maximilianocontieri.com/code-smell-17-global-functions

https://maximilianocontieri.com/code-smell-18-static-functions

https://maximilianocontieri.com/code-smell-19-optional-arguments

https://maximilianocontieri.com/code-smell-20-premature-optimization

https://maximilianocontieri.com/code-smell-21-anonymous-functions-abusers

https://maximilianocontieri.com/code-smell-22-helpers

https://maximilianocontieri.com/code-smell-23-instance-type-checking

https://maximilianocontieri.com/code-smell-24-boolean-coercions

https://maximilianocontieri.com/code-smell-25-pattern-abusers

https://maximilianocontieri.com/code-smell-26-exceptions-polluting

https://maximilianocontieri.com/code-smell-27-associative-arrays

https://maximilianocontieri.com/code-smell-28-setters

https://maximilianocontieri.com/code-smell-29-settingsconfigs

https://maximilianocontieri.com/code-smell-30-mocking-business

https://maximilianocontieri.com/code-smell-31-accidental-methods-on-business-objects

https://maximilianocontieri.com/code-smell-32-singletons

https://maximilianocontieri.com/code-smell-33-abbreviations

https://maximilianocontieri.com/code-smell-34-too-many-attributes

https://maximilianocontieri.com/code-smell-35-state-as-properties

https://maximilianocontieri.com/code-smell-36-switchcaseelseifelseif-statements

https://maximilianocontieri.com/code-smell-37-protected-attributes

https://maximilianocontieri.com/code-smell-38-abstract-names

https://maximilianocontieri.com/code-smell-39-new-date

https://maximilianocontieri.com/code-smell-40-dtos

https://maximilianocontieri.com/code-smell-41-regular-expression-abusers

https://maximilianocontieri.com/code-smell-42-warningsstrict-mode-off

https://maximilianocontieri.com/code-smell-43-concrete-classes-subclassified

https://maximilianocontieri.com/code-smell-44-magic-corrections

https://maximilianocontieri.com/code-smell-45-not-polymorphic

https://maximilianocontieri.com/code-smell-46-repeated-code

https://maximilianocontieri.com/code-smell-47-diagrams

https://maximilianocontieri.com/code-smell-48-code-without-standards

https://maximilianocontieri.com/code-smell-49-caches

https://maximilianocontieri.com/code-smell-50-object-keys

https://maximilianocontieri.com/code-smell-51-double-negatives

https://maximilianocontieri.com/code-smell-52-fragile-tests

https://maximilianocontieri.com/code-smell-53-explicit-iteration

https://maximilianocontieri.com/code-smell-54-anchor-boats

https://maximilianocontieri.com/code-smell-55-object-orgy

https://maximilianocontieri.com/code-smell-56-preprocessors

https://maximilianocontieri.com/code-smell-57-versioned-functions

https://maximilianocontieri.com/code-smell-58-yo-yo-problem

https://maximilianocontieri.com/code-smell-59-basic-do-functions

https://maximilianocontieri.com/code-smell-60-global-classes

https://maximilianocontieri.com/code-smell-61-coupling-to-classes

https://maximilianocontieri.com/code-smell-62-flag-variables

https://maximilianocontieri.com/code-smell-63-feature-envy

https://maximilianocontieri.com/code-smell-64-inappropriate-intimacy

https://maximilianocontieri.com/code-smell-65-variables-named-after-types

https://maximilianocontieri.com/code-smell-66-shotgun-surgery

https://maximilianocontieri.com/code-smell-67-middle-man

https://maximilianocontieri.com/code-smell-68-getters

https://maximilianocontieri.com/code-smell-69-big-bang-javascript-ridiculous-castings

https://maximilianocontieri.com/code-smell-70-anemic-model-generators

https://maximilianocontieri.com/code-smell-71-magic-floats-disguised-as-decimals

https://maximilianocontieri.com/code-smell-72-return-codes

https://maximilianocontieri.com/code-smell-73-exceptions-for-expected-cases

https://maximilianocontieri.com/code-smell-74-empty-lines

https://maximilianocontieri.com/code-smell-75-comments-inside-a-method

https://maximilianocontieri.com/code-smell-76-generic-assertions

https://maximilianocontieri.com/code-smell-77-timestamps

https://maximilianocontieri.com/code-smell-78-callback-hell

https://maximilianocontieri.com/code-smell-79-theresult

https://maximilianocontieri.com/code-smell-80-nested-trycatch

https://maximilianocontieri.com/code-smell-81-result

https://maximilianocontieri.com/code-smell-82-tests-violating-encapsulation

https://maximilianocontieri.com/code-smell-83-variables-reassignment

https://maximilianocontieri.com/code-smell-84-max-less-min-javascript

https://maximilianocontieri.com/code-smell-85-and-functions

https://maximilianocontieri.com/code-smell-86-mutable-const-arrays

https://maximilianocontieri.com/code-smell-87-inconsistent-parameters-sorting

https://maximilianocontieri.com/code-smell-88-lazy-initialization

https://maximilianocontieri.com/code-smell-89-math-feature-envy

https://maximilianocontieri.com/code-smell-90-implementative-callback-events

https://maximilianocontieri.com/code-smell-91-test-asserts-without-description

https://maximilianocontieri.com/code-smell-92-isolated-subclasses-names

https://maximilianocontieri.com/code-smell-93-send-me-anything

https://maximilianocontieri.com/code-smell-94-too-many-imports

https://maximilianocontieri.com/code-smell-95-premature-classification

https://maximilianocontieri.com/code-smell-96-my-objects

https://maximilianocontieri.com/code-smell-97-error-messages-without-empathy

https://maximilianocontieri.com/code-smell-98-speling-mistakes

https://maximilianocontieri.com/code-smell-99-first-second

https://maximilianocontieri.com/code-smell-100-goto

https://maximilianocontieri.com/code-smell-101-comparison-against-booleans

https://maximilianocontieri.com/code-smell-102-arrow-code

https://maximilianocontieri.com/code-smell-103-double-encapsulation

https://maximilianocontieri.com/code-smell-104-assert-true

https://maximilianocontieri.com/code-smell-105-comedian-methods

https://maximilianocontieri.com/code-smell-106-production-dependent-code

https://maximilianocontieri.com/code-smell-107-variables-reuse

https://maximilianocontieri.com/code-smell-108-float-assertions

https://maximilianocontieri.com/code-smell-109-automatic-properties

https://maximilianocontieri.com/code-smell-110-switches-with-defaults

https://maximilianocontieri.com/code-smell-111-modifying-collections-while-traversing

https://maximilianocontieri.com/code-smell-112-testing-private-methods

https://maximilianocontieri.com/code-smell-113-data-naming

https://maximilianocontieri.com/code-smell-114-empty-class

https://maximilianocontieri.com/code-smell-115-return-true

https://maximilianocontieri.com/code-smell-116-variables-declared-with-var

https://maximilianocontieri.com/code-smell-117-unrealistic-data

https://maximilianocontieri.com/code-smell-118-return-false

https://maximilianocontieri.com/code-smell-119-stairs-code

https://maximilianocontieri.com/code-smell-120-sequential-ids

https://maximilianocontieri.com/code-smell-121-string-validations

https://maximilianocontieri.com/code-smell-122-primitive-obsession

https://maximilianocontieri.com/code-smell-123-mixed-what-and-how

https://maximilianocontieri.com/code-smell-124-divergent-change

https://maximilianocontieri.com/code-smell-125-is-a-relationship

https://maximilianocontieri.com/code-smell-126-fake-null-object

https://maximilianocontieri.com/code-smell-127-mutable-constants

https://maximilianocontieri.com/code-smell-128-non-english-coding

https://maximilianocontieri.com/code-smell-129-structural-optimizations

https://maximilianocontieri.com/code-smell-130-addressimpl

https://maximilianocontieri.com/code-smell-131-zero-argument-constructor

https://maximilianocontieri.com/code-smell-132-exception-try-too-broad

https://maximilianocontieri.com/code-smell-133-hardcoded-if-conditions

https://maximilianocontieri.com/code-smell-134-specialized-business-collections

https://maximilianocontieri.com/code-smell-135-interfaces-with-just-one-realization

https://maximilianocontieri.com/code-smell-136-classes-with-just-one-subclass

https://maximilianocontieri.com/code-smell-137-inheritance-tree-too-deep

https://maximilianocontieri.com/code-smell-138-packages-dependency

https://maximilianocontieri.com/code-smell-139-business-code-in-the-user-interface

https://maximilianocontieri.com/code-smell-140-short-circuit-evaluation

https://maximilianocontieri.com/code-smell-141-iengine-avehicle-implcar

https://maximilianocontieri.com/code-smell-142-queries-in-constructors

https://maximilianocontieri.com/code-smell-143-data-clumps

https://maximilianocontieri.com/code-smell-144-fungible-objects

https://maximilianocontieri.com/code-smell-145-short-circuit-hack

https://maximilianocontieri.com/code-smell-146-getter-comments

https://maximilianocontieri.com/code-smell-147-too-many-methods

https://maximilianocontieri.com/code-smell-148-todos

https://maximilianocontieri.com/code-smell-149-optional-chaining

https://maximilianocontieri.com/code-smell-150-equal-comparison

https://maximilianocontieri.com/code-smell-151-commented-code

https://maximilianocontieri.com/code-smell-152-logical-comment

https://maximilianocontieri.com/code-smell-153-too-long-names

https://maximilianocontieri.com/code-smell-154-too-many-variables

https://maximilianocontieri.com/code-smell-155-multiple-promises

https://maximilianocontieri.com/code-smell-156-implicit-else

https://maximilianocontieri.com/code-smell-157-balance-at-0

https://maximilianocontieri.com/code-smell-158-variables-not-variable

https://maximilianocontieri.com/code-smell-159-mixedcase

https://maximilianocontieri.com/code-smell-160-invalid-id-9999

https://maximilianocontieri.com/code-smell-161-abstractfinalundefined-classes

https://maximilianocontieri.com/code-smell-162-too-many-parentheses

https://maximilianocontieri.com/code-smell-163-collection-in-name

https://maximilianocontieri.com/code-smell-164-mixed-indentations

https://maximilianocontieri.com/code-smell-165-empty-exception-blocks

https://maximilianocontieri.com/code-smell-166-low-level-errors-on-user-interface

https://maximilianocontieri.com/code-smell-167-hashing-comparison

https://maximilianocontieri.com/code-smell-168-undocumented-decisions

https://maximilianocontieri.com/code-smell-169-glued-methods

https://maximilianocontieri.com/code-smell-170-refactor-with-functional-changes

https://maximilianocontieri.com/code-smell-171-plural-classes

https://maximilianocontieri.com/code-smell-172-default-argument-values-not-last

https://maximilianocontieri.com/code-smell-173-broken-windows

https://maximilianocontieri.com/code-smell-174-class-name-in-attributes

https://maximilianocontieri.com/code-smell-175-changes-without-coverage

https://maximilianocontieri.com/code-smell-176-changes-in-essence

https://maximilianocontieri.com/code-smell-177-missing-small-objects

https://maximilianocontieri.com/code-smell-178-subsets-violation

https://maximilianocontieri.com/code-smell-179-known-bugs

https://maximilianocontieri.com/code-smell-180-bitwise-optimizations

https://maximilianocontieri.com/code-smell-181-nested-classes

https://maximilianocontieri.com/code-smell-182-over-generalization

https://maximilianocontieri.com/code-smell-183-obsolete-comments

https://maximilianocontieri.com/code-smell-184-exception-arrow-code

https://maximilianocontieri.com/code-smell-185-evil-regular-expressions

https://maximilianocontieri.com/code-smell-186-hardcoded-business-conditions

https://maximilianocontieri.com/8-lls-po-spq-sli

https://maximilianocontieri.com/code-smell-188-redundant-parameter-names

https://maximilianocontieri.com/code-smell-189-not-sanitized-input

https://maximilianocontieri.com/code-smell-190-unnecessary-properties

https://maximilianocontieri.com/code-smell-191-misplaced-responsibility

https://maximilianocontieri.com/code-smell-192-optional-attributes

https://maximilianocontieri.com/code-smell-193-switch-instead-of-formula

https://maximilianocontieri.com/code-smell-194-missing-interval

https://maximilianocontieri.com/code-smell-195-yoda-conditions

https://maximilianocontieri.com/code-smell-196-javascript-array-constructors

https://maximilianocontieri.com/code-smell-197-gratuitous-context

https://maximilianocontieri.com/code-smell-198-hidden-assumptions

https://maximilianocontieri.com/code-smell-199-gratuitous-booleans

https://maximilianocontieri.com/code-smell-200-poltergeist

https://maximilianocontieri.com/code-smell-201-nested-ternaries

https://maximilianocontieri.com/code-smell-202-god-constant-class

https://maximilianocontieri.com/code-smell-203-irrelevant-test-information

https://maximilianocontieri.com/code-smell-204-tests-depending-on-dates

https://maximilianocontieri.com/code-smell-205-code-in-destructors

https://maximilianocontieri.com/code-smell-206-long-ternaries

https://maximilianocontieri.com/code-smell-207-dynamic-methods

https://maximilianocontieri.com/code-smell-208-null-island

https://maximilianocontieri.com/code-smell-209-side-effects

https://maximilianocontieri.com/code-smell-210-dynamic-properties

https://maximilianocontieri.com/code-smell-211-tab-over-spaces

https://maximilianocontieri.com/code-smell-212-elvis-operator

https://maximilianocontieri.com/code-smell-213-hoisting

https://maximilianocontieri.com/code-smell-214-duplicate-parameter-names

https://maximilianocontieri.com/code-smell-215-deserializing-object-vulnerability

https://maximilianocontieri.com/code-smell-216-fat-interface

https://maximilianocontieri.com/code-smell-217-empty-implementation

https://maximilianocontieri.com/code-smell-218-magic-concatenation

https://maximilianocontieri.com/code-smell-219-looping-from-index-0

https://maximilianocontieri.com/code-smell-220-return-tuple

https://maximilianocontieri.com/code-smell-221-missing-break-in-switch

https://maximilianocontieri.com/code-smell-222-comma-operator

https://maximilianocontieri.com/code-smell-223-racial-naming

https://maximilianocontieri.com/code-smell-224-deodorant-comments

https://maximilianocontieri.com/code-smell-225-pass-by-reference

https://maximilianocontieri.com/code-smell-226-mixed-priorities

https://maximilianocontieri.com/code-smell-227-cowboy-coding

https://maximilianocontieri.com/code-smell-228-multiple-classes-per-file

https://maximilianocontieri.com/code-smell-229-red-tape

https://maximilianocontieri.com/code-smell-230-schrodinger-code

https://maximilianocontieri.com/code-smell-231-redundant-data

https://maximilianocontieri.com/code-smell-232-reusable-code

https://maximilianocontieri.com/code-smell-233-collections-count

... and many more to come.

Photo by Richárd Ecsedi on Unsplash

Smells are certain structures in the code that suggest (sometimes they scream for) the possibility of refactoring

Martin Fowler

https://maximilianocontieri.com/software-engineering-great-quotes

Part of the objective of this series of articles is to generate spaces for debate and discussion on software design.

https://maximilianocontieri.com/object-design-checklist

We look forward to your comments and suggestions on this article.

Original Thread on Twitter

How to Find the Stinky Parts of Your Code

Code Smells