Rules

• Rules
  • Rules support matrix by techno
  • Rules to be reworked / measured / clarified
  • Deprecated rules
  • Refused / Deleted rules

Rules support matrix by techno

This matrix lists all the rules identified as implementable within the standard creedengo plugin.

Some are applicable for different technologies.

• ✅ Rule included in current version of creedengo
• 🚧 Rule implementation in progress
• 🚀 Rule to implement
• ❓ Rule to analyze for applicability
• 🚫 Non applicable rule

Rule key	Name	Description	Reference/Validation	Java	Php	JS	Python	Rust	C#	HTML	Mobile Android	Mobile iOS	Source reference
CRJVM205	Force usage of FetchType LAZY for collections on JPA entities			🚧	❓	❓	❓	❓	❓	🚫	🚫	🚫
CRJVM206	Avoid N+1 selects problem			🚧	❓	❓	❓	❓	❓	🚫	🚫	🚫
CRJVM207	Customer data must have end-of-life information			🚧	❓	❓	❓	❓	❓	❓	🚫	🚫
CRJVM???	Persistence Java : Avoid Joints on non indexed columns			🚧	❓	❓	❓	❓	❓	🚫	🚫	🚫
GCI1	Calling a Spring repository inside a loop or a stream	The use of Spring repository in a loop or a stream induces unnecessary calculations by the CPU and therefore superfluous energy consumption.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI2	Multiple if-else statements	Using too many conditional if-else statements will impact performance since JVM will have to compare the conditions. Prefer using a switch statement instead of multiple if-else if possible, or refactor your code to reduce conditonnal statements on the same variable. Switch statement has a performance advantage over if – else.		✅	✅	🚀	✅	🚀	🚀	🚫	🚫	🚫	documentation
GCI3	Getting the size of the collection in the loop	When iterating over any collection, fetch the size of the collection in advance to avoid fetching it on each iteration, this saves CPU cycles, and therefore consumes less power.		✅	✅	🚀	🚫	🚀	🚫	🚫	🚫	🚫	documentation
GCI4	Use global variables	When using a global variable, the interpretation engine must check: 1) that it exists in the current scope, in the one above, etc. ; 2) the variable has a value; 3) ... To avoid all these checks, it is often possible to pass the useful variables as arguments of routines, making them local. This process saves computational time (CPU cycles).	cnumr best practices (3rd edition) BP_050 (no longer exists in edition 4)	🚫	✅	🚀	✅	🚀	🚫	🚫	🚫	🚫	documentation
GCI5	Usage of preparedStatement instead of Statement	SQL will only commit the query once, whereas if you used only one statement, it would commit the query every time and thus induce unnecessary calculations by the CPU and therefore superfluous energy consumption.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI7	Rewrite native getter/setters	Overloading them lengthens the compilation and execution times of these methods, which are usually much better optimized by the language than by the developer.	cnumr best practices (3rd edition) BP_062 (no longer exists in edition 4)	🚫	🚫	🚀	✅	🚀	🚫	🚫	🚫	🚫	documentation
GCI9	Importing everything from library should be avoided	ESLint key : @creedengo/no-import-all-from-library /// type : Common		❓	❓	✅	❓	❓	❓	🚫	🚫	🚫	documentation
GCI10	Use unoptimized vector images	Less heavy SVG images using less bandwidth	cnumr best practices (3rd edition) BP_036	🚀	🚀	🚀	✅	🚀	🚫	❓	🚫	🚫	documentation
GCI11	Multiple access of same DOM element should be limited	ESLint key : @creedengo/no-multiple-access-dom-element /// type : Front-end		🚫	❓	✅	🚫	🚫	❓	🚫	🚫	🚫	documentation
GCI12	Multiple style changes should be batched	ESLint key : @creedengo/no-multiple-style-changes /// type : Front-end		🚫	❓	✅	🚫	🚫	❓	🚫	🚫	🚫	documentation
GCI13	API collections should be preferred with pagination	ESLint key : @creedengo/prefer-collections-with-pagination /// type : Back-end		❓	❓	✅	❓	❓	❓	🚫	🚫	🚫	documentation
GCI22	The use of methods for basic operations	Using methods for basic operations consumes additional system resources. The interpreter must in effect and solve the objects and then the methods, just to carry out these simple operations of the language.	cnumr best practices (3rd edition) BP_048 (no longer exists in edition 4)	🚫	🚫	🚀	🚀	🚀	🚫	🚫	🚫	🚫	documentation
GCI24	Returned SQL results should be limited	ESLint key : @creedengo/limit-db-query-results /// type : Back-end		🚧	🚀	✅	✅	🚀	🚀	🚫	🚫	🚫	documentation
GCI25	Images should not have an empty source attribute	ESLint key : @creedengo/no-empty-image-src-attribute /// type : Front-end		❓	❓	✅	❓	❓	❓	🚀	🚫	🚫	documentation
GCI26	Shorthand CSS notations should be used to reduce stylesheets size	ESLint key : @creedengo/prefer-shorthand-css-notations /// type : Front-end		❓	❓	✅	❓	❓	❓	🚫	🚫	🚫	documentation
GCI27	Usage of system.arraycopy to copy arrays	Programs spend most of the time in loops. These can be resource consuming, especially when they integrate heavy processing (IO access). Moreover, the size of the data and processing inside the loops will not allow full use of hardware mechanisms such as the cache or compiler optimization mechanisms.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI28	Optimize read file exceptions			✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI29	CSS animations should be avoided	ESLint key : @creedengo/avoid-css-animations /// type : Front-end		❓	❓	✅	❓	❓	❓	🚫	🚫	🚫	documentation
GCI30	Print stylesheet should be provided	ESLint key : @creedengo/provide-print-css /// type : Front-end		❓	❓	✅	❓	❓	❓	🚫	🚫	🚫	documentation
GCI31	Lighter formats should be used for image files	ESLint key : ... /// type : ...		🚧	❓	✅	❓	❓	❓	🚀	🚫	🚫	documentation
GCI32	Initialize builder/buffer with the appropriate size	If you know in advance how many characters would be appended, initialize builder/buffer with the appropriate size. They will thus never have to be resized. This saves CPU cycles and therefore consumes less energy.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI35	Using try...catch calls (on File Not Found error)	When an exception is thrown, a variable (the exception itself) is created in the catch block and destroyed at the end of the block. Creating this variable and destroying it consumes CPU cycles and RAM unnecessarily. That is why it is important not to use this construction and to prefer, as much as possible, a logical test. This new rule replace old GCI34 only for a particular use case (FileNotFoundException)	cnumr best practices (3rd edition) BP_047 (no longer exists in edition 4)	🚫	✅	🚀	✅	🚀	🚫	🚫	🚫	🚫	documentation
GCI36	Autoplay should be avoided for video and audio content	Autoplaying media consumes unnecessary energy, especially when users might not be actively engaging with the content.	cnumr best practices BP_4003	🚫	🚫	✅	🚫	🚫	🚫	🚧	🚫	🚫	documentation
GCI66	Use single quote (') instead of quotation mark (")	The shape using the quotation marks allows the developer to insert variables that will be substituted at run time. But if the string does not have a variable, use quotes instead. Thus, language will not look for variables to subtituture, which will reduce the consumption of CPU cycles.	cnumr best practices (3rd edition) BP_066 (no longer exists in edition 4)	🚫	🚫	🚫	🚫	🚀	🚫	🚫	🚫	🚫	documentation
GCI67	Use the $i++ variable during an iteration	The $i++ form has the disadvantage of generating a tem-porary variable during incrementation, which is not the case with the ++$i form.	cnumr best practices (3rd edition) BP_067 (no longer exists in edition 4)	✅	✅	🚀	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI69	Calling a loop invariant function in a loop condition	Avoid calling loop invariant functions in loop conditions.	cnumr best practices (3rd edition) BP_069 (no longer exists in edition 4)	✅	✅	🚀	🚫	🚀	✅	🚫	🚫	🚫	documentation
GCI72	Perform an SQL query inside a loop	Servers are optimized to process multiple selections, insertions, or changes in a single query or transaction. consume CPU cycles, RAM, and bandwidth unnecessarily.	cnumr best practices (3rd edition) BP_072	✅	✅	🚀	✅	🚀	✅	🚫	🚫	🚫	documentation
GCI74	Write SELECT * FROM	The database server must resolve the fields based on the schema. If you are familiar with the diagram, it is strongly recommended to name the fields.	cnumr best practices (3rd edition) BP_074 (no longer exists in edition 4)	✅	✅	🚀	✅	🚀	🚀	🚫	🚫	🚫	documentation
GCI75	Don't concatenate strings in loops	Avoid repeated string allocations and consider using a StringBuilder instead.		🚫	❓	❓	❓	❓	✅	🚫	🚫	🚫	documentation
GCI76	Usage of static collections	Avoid usage of static collections. If you want to use static collections make them final and create for example a singleton if needed containing the collections. The static fields are more complicated for the Garbage Collector to manage and can lead to memory leaks.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI77	Usage Pattern.compile() in a non-static context	Avoid using Pattern.compile() in a non-static context. This operation requires a non negligible amount of computational power, Using a single match saves CPU cycles and RAM consumption.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI78	Const parameter in batch update	Don't set const parameter in batch update => Put its in query. Creating this parameter and destroying it consumes CPU cycles and RAM unnecessarily.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI79	Free resources	try-with-resources Statement needs to be implemented for any object that implements the AutoCloseable interface, it save computer resources.		✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI81	Specify struct layouts	When possible, specify struct layouts to optimize their memory footprint		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI82	Make variable constant	A variable is never reassigned and can be made constant		✅	🚀	🚀	🚀	🚀	✅	🚫	🚫	🚫	documentation
GCI83	Replace Enum ToString() with nameof	When no string format is applied, use nameof instead of ToString() for performance		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI84	Avoid async void methods	Use async Task methods instead, for performance, stability and testability		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI85	Make type sealed	Seal types that don't need inheritance for performance reasons		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI86	GC.Collect should not be called	In most cases, the cost of calling GC.Collect far outweighs the benefits		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI87	Use collection indexer	Collection indexers should be used instead of Linq, when available		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI88	Dispose resource asynchronously	Resources that implement IAsyncDisposable should be disposed asynchronously		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI89	Avoid using function cache without limit	If a function has decorators without max size cache, the program will store unlimited data		❓	❓	❓	✅	❓	❓	❓	🚫	🚫	documentation
GCI90	Use Cast instead of Select to cast	Cast is optimized for this scenario and should be used		❓	❓	❓	❓	❓	✅	❓	🚫	🚫	documentation
GCI91	Use filter feature before sort elements	Filter elements before sorting them for improved efficiency		🚧	❓	❓	❓	❓	✅	❓	🚫	🚫	documentation
GCI92	Use string.Length instead of comparison with empty string	Comparing a string to an empty string is unnecessary and can be replaced by a call to string.Length which is more performant and more readable.		🚫	🚫	🚫	🚫	🚫	✅	🚫	🚫	🚫	documentation
GCI93	Return Task directly	Consider returning a Task directly instead of a single await		❓	❓	❓	❓	❓	✅	❓	🚫	🚫	documentation
GCI94	Use orElseGet instead of orElse	Parameter of orElse() is evaluated, even when having a non-empty Optional. Supplier method of orElseGet passed as an argument is only executed when an Optional value isn’t present. Therefore, using orElseGet() will save computing time.	Optimized use of Java Optional Else	✅	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI95	Avoid querying SQL columns that are not used	When a database is queried without an ORM, every column that is queried should be used afterward somewhere in the function.	cnumr best practices (3rd edition) BP_075	🚧	❓	❓	❓	❓	❓	❓	🚫	🚫	documentation
GCI96	Data / AI : Pandas - Avoid Reading Unnecessary Columns in CSV Files	Reading CSV files without explicitly specifying which columns to load leads to unnecessary data loading and increases memory and energy consumption.		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI97	Optimize square computation (scalar vs vectorized method)	In Python, if you want to square x, you can do x*x or x**2.		❓	❓	❓	✅	❓	❓	❓	🚫	🚫	documentation
GCI98	Avoid raising Runtime Exceptions when a check is possible	You should not catch RuntimeException. They produce large objects and represent a problem in the program that should be fixed, not handled.	Unchecked Exceptions The Controversy (9.3. Les classes Exception, RunTimeException et Error)[https://www.jmdoudoux.fr/java/dej/chap-exceptions.htm#exceptions-3]	🚧	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI99	Data : Avoid CSV Format	The Parquet format is faster to write to, lighter in weight and faster to read data from. It is suitable for use cases where there would be a lot of data I/O, especially with Cloud storage.		🚀	🚀	🚀	✅	🚀	🚀	🚀	🚫	🚫	documentation
GCI100	AI : Wrap PyTorch Inference in torch.no_grad()	Using a PyTorch model in evaluation mode without wrapping inference in torch.no_grad() leads to unnecessary gradient tracking		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI101	AI : Avoid Bias in Conv Layers Before Batch Norm	Disable bias in convolutional layers when it's followed by a batch norm layer		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI102	AI : Use pinned memory on DataLoader when using GPU	This rule applies to PyTorch data loading, where the use of pinned memory can significantly optimize data transfer between CPU and GPU.		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI103	Don't use .items() to iterate over a dictionary when only keys or values are needed	Avoid using .items() if you only use the key or the value, as this creates an unnecessary tuple, leading to increased memory allocation and slower execution.		❓	❓	❓	✅	❓	❓	❓	🚫	🚫	documentation
GCI104	Data / AI : PyTorch - Create tensors directly from Torch	In PyTorch, prefer creating tensors directly using torch.rand, torch.tensor, or other Torch methods instead of converting from NumPy arrays. Avoid using torch.tensor(np.random.rand(...)) or similar patterns when the same result can be achieved directly with PyTorch.		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI105	Python String Concatenation	Python String Concatenation - Use Join Instead or f-Strings instead of +=		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI106	Avoid Square Root Operations In Loop	Using scalar math.sqrt (or numpy.sqrt on individual values) inside loops leads to inefficient code		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI107	Data : Avoid Iterative Matrix Operations	Use vectorization by the usage of the built-in functions of TensorFlow, NumPy or Pandas		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI108	Prefer Append Left	When you want to insert an element at the beginning of a list, it's better to use a deques or a double linkedlist.		❓	❓	❓	✅	❓	❓	❓	🚫	🚫	documentation
GCI109	Avoid Using Exceptions for Control Flow	Using exceptions for control flow (loops, defaults, branching) is expensive in Python. Prefer idiomatic alternatives like dict.get(), enumerate(), getattr() with defaults, or proper iteration patterns.		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI110	Python: Avoid wildcard imports (from module import *)	Wildcard imports bind many names and run module top‑level init, slightly increasing import time and memory. Prefer explicit named imports		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI111	Logging format interpolation	When logging with formatted string, prefer using %s with kwargs, which will be deferred until it cannot be avoided, instead of immediate formatter .format() or f"".		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI112	Reduce memory footprint of dataclasses	Using slots can be an effective way to optimize memory usage in Python classes and improve the performance of memory-intensive applications. It is a minor remediation cost to add slots in class definitions and can have significant benefits in terms of memory efficiency.		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI113	Prefer XGBoost to RandomForest	Using XGBoost offers a more optimized and eco-friendly alternative with competitive accuracy than RandomForest.		🚫	🚫	🚫	🚀	🚫	🚫	🚫	🚫	🚫	documentation
GCI203	Detect unoptimized file formats	When it is possible, to use svg format image over other image format		🚧	🚀	🚀	✅	🚀	🚀	🚫	🚫	🚫	documentation
GCI404	Avoid list comprehension in iterations	Use generator comprehension instead of list comprehension in for loop declaration		🚫	🚫	🚫	✅	🚫	🚫	🚫	🚫	🚫	documentation
GCI500	Batch: Sensor Coalesce	Use maxReportLatencyUs to batch sensor events and reduce CPU wake-ups.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI501	Batch: Job Coalesce	Use JobScheduler to batch network operations and reduce radio wake-ups.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI502	Bottleneck: Internet In The Loop	Avoid network calls inside loops to reduce radio usage.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI503	Bottleneck: Wifi Multicast Lock	Release Wifi multicast locks to allow the radio to sleep.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI504	Bottleneck: Uncompressed Data Transmission	Compress data before transmission to save bandwidth and energy.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI505	Idleness: Keep Screen On (addFlags)	Avoid keeping the screen on via addFlags to save battery.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI506	Idleness: Keep Screen On (setFlags)	Avoid keeping the screen on via setFlags to save battery.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI507	Idleness: Keep Cpu On	Avoid keeping the CPU on with PARTIAL_WAKE_LOCK.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI508	Idleness: Durable Wake Lock	Release wake locks promptly to allow the device to sleep.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI509	Idleness: Rigid Alarm	Use inexact alarms to allow the system to batch wake-ups.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI510	Idleness: Continuous Rendering	Avoid RENDERMODE_CONTINUOUSLY for OpenGL surfaces.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI511	Idleness: Keep Voice Awake	Release voice recognition resources when not needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI512	Leakage: Camera Leak	Release camera resources when no longer needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI513	Leakage: Location Leak	Stop location updates when no longer needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI514	Leakage: SensorManager Leak	Unregister sensor listeners when no longer needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI515	Leakage: Media Leak (MediaRecorder)	Release MediaRecorder when no longer needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI516	Leakage: Media Leak (MediaPlayer)	Release MediaPlayer when no longer needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI517	Optimized API: Fused Location	Use FusedLocationProviderClient instead of raw GPS.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI518	Optimized API: Bluetooth Low-Energy	Use BLE APIs instead of classic Bluetooth.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI519	Power: Charge Awareness	Monitor battery level and adapt behavior accordingly.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI520	Power: Save Mode Awareness	Detect power save mode and reduce activity.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI521	Sobriety: Thrifty Motion Sensor	Use appropriate sensor delay for motion sensors.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI522	Sobriety: Brightness Override	To avoid draining the battery, iOS and Android devices adapt the brightness of the screen depending on the environment light.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI523	Sobriety: Thrifty Geolocation (minTime)	High-precision geolocation typically requires more power from the device's GPS hardware.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI524	Sobriety: Thrifty Geolocation Criteria	Use appropriate accuracy criteria for geolocation.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI525	Sobriety: Thrifty BLE (setAdvertiseMode)	Use low-power BLE advertising mode.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI526	Sobriety: Thrifty BLE (requestConnectionPriority)	Use balanced BLE connection priority.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI527	Sobriety: Thrifty Geolocation (minDistance)	Set minDistance > 0 for location updates.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI528	Sobriety: Vibration Free	Avoid using the device vibrator.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI529	Sobriety: Thrifty Notification	Avoid vibration/sound in notifications.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI530	Sobriety: Torch Free	Turning on the torch mode programmatically must absolutely be avoided because the flashlight is one of the most energy-intensive component.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI531	Sobriety: High Frame Rate	Avoid requesting high frame rates.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI532	Privacy: Google Tracker	Avoid using Google tracking services.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI533	GDPR: Google Ads Consent	Ensure Google Ads consent is properly implemented for GDPR compliance.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI534	Privacy: Tracking Id	Avoid tracking users via TelephonyManager#getDeviceId().		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	✅	documentation
GCI540	Batch: Service Boot Time (XML)	Avoid starting services at device boot to reduce startup energy.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI541	Idleness: Keep Screen On (XML)	Avoid android:keepScreenOn="true" in layouts.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI542	Idleness: Keep Cpu On (XML)	Avoid WAKE_LOCK permission when not needed.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI543	Power: Companion In Background (XML)	Avoid requesting BIND_COMPANION_DEVICE_SERVICE.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI544	Power: Ignore Battery Optimizations (XML)	Avoid REQUEST_IGNORE_BATTERY_OPTIMIZATIONS.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI545	Power: Charge Awareness (XML)	Declare battery-related broadcast receivers.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI546	Power: Save Mode Awareness (XML)	Declare power save mode broadcast receivers.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI547	Sobriety: Dark UI (Bright Colors)	Avoid bright colors in dark theme layouts.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI548	Sobriety: Dark UI (Theme)	Provide a dark theme for the app.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
GCI549	Sobriety: Hardware Acceleration (XML)	Disable hardware acceleration when not needed to reduce RAM usage.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	🚫	documentation
	Use official social media sharing buttons	These JavaScript plugins are very resource-intensive: to work, they require a large number of requests and download heavy files. It is better to prefer direct links.	cnumr best practices (3rd edition) BP_019	🚫	🚫	🚀	🚫	🚫	🚫	🚀	🚫	🚫
	Non-grouped similar CSS declarations	When multiple Document Object Model (DOM) elements have common CSS properties, declare them together in the same style sheet. This method reduces the weight of CSS.	cnumr best practices (3rd edition) BP_025	🚫	🚫	🚧	🚫	🚫	🚫	🚫	🚫	🚫
	Non-standard fonts used	Prefer standard fonts, as they are already present on the user's computer, so they do not need to download them. This saves bandwidth, while speeding up the display of the site.	cnumr best practices (3rd edition) BP_029	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫
	Non-outsourced CSS and Javascript	If you include CSS or JavaScript code in the body of the HTML file, while the HTML file is used by several pages (or even the entire site), this code must be transferred for each page requested by the user, which increases the volume of data transmitted.	cnumr best practices (3rd edition) BP_032	🚫	🚫	🚀	🚫	🚫	🚫	🚀	🚫	🚫
	Resize images browser-side	Do not resize images using the HEIGHT and WIDTH attributes of the HTML code. This approach requires transferring these images to their original size, wasting bandwidth and CPU cycles.	cnumr best practices (3rd edition) BP_034	🚫	🚫	🚧	🚫	🚫	🚫	🚀	🚫	🚫
	Modify the DOM when traversing it	Modifying the DOM (Document Object Model) as you traverse it can lead to situations where the loop becomes very resource-intensive, especially CPU cycles.	cnumr best practices (3rd edition) BP_041	🚫	🚫	🚧	🚫	🚫	🚫	🚫	🚫	🚫
	Edit DOM elements to make it invisible	When an element of the Document Object Model (DOM) needs to be modified by several properties, each change in style or content will generate a repaint or reflow.	cnumr best practices (3rd edition) BP_042	🚫	🚫	🚀	🚫	🚫	🚫	🚫	🚫	🚫
GCI535	Use native Intl.NumberFormat to format numbers	There's no need to use a library to display formatted numbers in a recent browser. Use Intl.NumberFormat for that use case.		🚫	🚫	🚧	🚫	🚫	🚫	🚫	🚫	🚫	documentation
GCI603	Animation Free	Animations play a crucial role in creating a dynamic UI but should be checked for unnecessary usage to avoid draining the battery.		🚫	🚫	🚫	🚫	🚫	🚫	🚫	🚫	✅	documentation

Rules to be reworked / measured / clarified

This table lists rules proposed by the community but they have to be reworked / measured / clarified before being implemented in creedengo plugins. (Issues and PR are closed, but they can be reopen once rework launched)

Rule key	Language	Name	Description	Invalidation
CRJVM204	Java	Detect unoptimized file formats	We have to clarify and rework this rule for Java before accepting the implementation	Github discussion - issue Github discussion - PR
GCI22	Java	The use of methods for basic operations	We have to measure this rule for Java before accepting the implementation	Github discussion - issue Github discussion - PR
GCI22	PHP	The use of methods for basic operations	We have to measure this rule for PHP before accepting the implementation	Github discussion - issue
GCI53	Java	Using arrays in foreach loops	No good arguments and not enough green measures.	Github discussion with sources
GRSP0007	PHP	Prefer using foreach	We have to clarify and measure this rule for PHP before accepting the implementation	Github discussion - PR
GRSP0008	PHP	Avoid using relative path	We have to clarify and measure this rule for PHP before accepting the implementation	Github discussion - PR
	Java	Avoid returning a JPA Entity in a RestController	We have to clarify and measure this rule for Java before accepting the implementation	Github discussion - issue Github discussion - PR

Deprecated rules

This table lists rules proposed by the community but deprecated in creedengo plugins with the justification. These rules will be completely deleted in next releases and moved to bottom deleted rules array.

Rule key	Language	Name	Description	Invalidation

Refused / Deleted rules

This table lists rules proposed by the community but refused or/and deleted in creedengo plugins with the justification.

Rule key	Language	Name	Description	Invalidation
CRDOM203	HTML	HTML page must contain a doctype tag	The difference in performance is negligible, this rule is more related to the user experience.	Github discussion with sources
CRPYT	Python	Use numpy array instead of standard list	The use of numpy library to perform array manipulation is more energy efficient than the use of the standard list functions.	Github discussion with measures
GCI4	Java	Avoid using global variables	Global variables do not exist in Java.	Github discussion with sources
GCI8	JavaScript	Avoid using high accuracy geolocation	The rule has been merged with the rule GCI523	Github discussion with sources
GCI34	Python	Using try...catch...finally calls	Implementation is too simple (only detection of presence of "try" statement) AND replaced by GCI35 rule	Github discussion with measures : general/java / python
GCI34	PHP	Using try...catch...finally calls	Implementation is too simple (only detection of presence of "try" statement) AND replaced by GCI35 rule	Github discussion with measures : general/java / php
GCI63	Java	Unnecessarily assigning values to variables	There are already 3 native SonarQube rules for Java.	Github discussion with sources
GCI66	Java	Use single quote (') instead of quotation mark (")	Finally, not applicable for Java	Discussed with core team
GCI66	JS	Use single quote (') instead of quotation mark (")	No difference in performance	Discussed with core team
GCI66	Python	Use single quote (') instead of quotation mark (")	Finally, not applicable for Python	Github discussion with sources
GCI66	PHP	Use single quote (') instead of quotation mark (")	Finally, not applicable for PHP	Github discussion with sources
GCI69	Python	Calling a loop invariant function in a loop condition	Finally, not applicable for Python	Github discussion with sources
GCI75	Java	Don't concatenate strings in loops	Optimizations on Java concatenation Strings are useless since JDK8	Github discussion with sources