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174 lines
6.5 KiB
Markdown
174 lines
6.5 KiB
Markdown
# 100 Go Mistakes and How to Avoid Them
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Source code of 📖 [100 Go Mistakes and How to Avoid Them](https://www.manning.com/books/100-go-mistakes-and-how-to-avoid-them), edited by Manning.
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**Note:** If you're struggling to afford the book, please DM me [@teivah](https://twitter.com/teivah).
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## Table of Contents
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### Chapter 1 - Introduction
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### Chapter 2 - Code and Project Organization
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* 1 - Unintended variable shadowing
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* 2 - Unnecessary nested code
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* 3 - Misusing init functions
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* 4 - Overusing getters and setters
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* 5 - Interface pollution
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* 6 - Interface on the producer side
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* 7 - Returning interfaces
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* 8 - `any` says nothing
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* 9 - [Being confused about when to use generics](https://teivah.medium.com/when-to-use-generics-in-go-36d49c1aeda)
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* 10 - Not being aware of the possible problems with type embedding
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* 11 - Not using the functional options pattern
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* 12 - Project misorganization (project structure and package organization)
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* 13 - Creating utility packages
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* 14 - Ignoring package name collisions
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* 15 - Missing code documentation
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* 16 - Not using linters
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### Chapter 3 - Data Types
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* 17 - Creating confusion with octal literals
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* 18 - Neglecting integer overflows
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* 19 - Not understanding floating-points
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* 20 - Not understanding slice length and capacity
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* 21 - Inefficient slice initialization
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* 22 - Being confused about nil vs. empty slice
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* 23 - Not properly checking if a slice is empty
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* 24 - Not making slice copies correctly
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* 25 - Unexpected side effects using slice append
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* 26 - Slice and memory leaks
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* 27 - Inefficient map initialization
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* 28 - Map and memory leaks
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* 29 - Comparing values incorrectly
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### Chapter 4 - Control Structures
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* 30 - Ignoring that elements are copied in `range` loops
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* 31 - Ignoring how arguments are evaluated in `range` loops (channels and arrays)
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* 32 - Ignoring the impacts of using pointer elements in `range` loops
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* 33 - Making wrong assumptions during map iterations (ordering and map insert during iteration)
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* 34 - Ignoring how the `break` statement work
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* 35 - Using `defer` inside a loop
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### Chapter 5 - Strings
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* 36 - Not understanding the concept of rune
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* 37 - Inaccurate string iteration
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* 38 - Misusing trim functions
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* 39 - Under-optimized strings concatenation
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* 40 - Useless string conversions
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* 41 - Substring and memory leaks
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### Chapter 6 - Functions and Methods
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* 42 - Not knowing which type of receiver to use
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* 43 - Never using named result parameters
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* 44 - Unintended side effects with named result parameters
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* 45 - Returning a nil receiver
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* 46 - Using a filename as a function input
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* 47 - Ignoring how defer arguments and receivers are evaluated (argument evaluation, pointer and value receivers)
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### Chapter 7 - Error Management
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* 48 - Panicking
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* 49 - Ignoring when to wrap an error
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* 50 - Comparing an error type inaccurately
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* 51 - Comparing an error value inaccurately
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* 52 - Handling an error twice
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* 53 - Not handling an error
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* 54 - Not handling defer errors
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### Chapter 8 - Concurrency: Foundations
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* 55 - Mixing up concurrency and parallelism
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* 56 - Thinking concurrency is always faster
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* 57 - Being puzzled about when to use channels or mutexes
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* 58 - Not understanding race problems (data races vs. race conditions and the Go memory model)
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* 59 - Not understanding the concurrency impacts of a workload type
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* 60 - Misunderstanding Go contexts
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### Chapter 9 - Concurrency: Practice
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* 61 - Propagating an inappropriate context
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* 62 - Starting a goroutine without knowing when to stop it
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* 63 - Not being careful with goroutines and loop variables
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* 64 - Expecting a deterministic behavior using select and channels
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* 65 - Not using notification channels
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* 66 - Not using nil channels
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* 67 - Being puzzled about channel size
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* 68 - Forgetting about possible side effects with string formatting (etcd data race example and deadlock)
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* 69 - Creating data races with append
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* 70 - Using mutexes inaccurately with slices and maps
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* 71 - Misusing `sync.WaitGroup`
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* 72 - Forgetting about `sync.Cond`
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* 73 - Not using `errgroup`
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* 74 - Copying a `sync` type
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### Chapter 10 - Standard Library
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* 75 - Providing a wrong time duration
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* 76 - `time.After` and memory leaks
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* 77 - JSON handling common mistakes
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* Unexpected behavior because of type embedding
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* JSON and the monotonic clock
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* Map of `any`
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* 78 - Common SQL mistakes
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* Forgetting that `sql.Open` doesn't necessarily establish connections to a database
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* Forgetting about connections pooling
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* Not using prepared statements
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* Mishandling null values
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* Not handling rows iteration errors
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* 79 - Not closing transient resources (HTTP body, `sql.Rows`, and `os.File`)
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* 80 - Forgetting the return statement after replying to an HTTP request
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* 81 - Using the default HTTP client and server
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### Chapter 11 - Testing
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* 82 - Not categorizing tests (build tags, environment variables, and short mode)
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* 83 - Not enabling the race flag
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* 84 - Not using test execution modes (parallel and shuffle)
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* 85 - Not using table-driven tests
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* 86 - Sleeping in unit tests
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* 87 - Not dealing with the time API efficiently
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* 88 - Not using testing utility packages (`httptest` and `iotest`)
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* 89 - Writing inaccurate benchmarks
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* Not resetting or pausing the timer
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* Making wrong assumptions about micro-benchmarks
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* Not being careful about compiler optimizations
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* Being fooled by the observer effect
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* 90 - Not exploring all the Go testing features
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* Code coverage
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* Testing from a different package
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* Utility functions
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* Setup and teardown
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### Chapter 12 - Optimizations
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* 91 - Not understanding CPU caches
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* CPU architecture
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* Cache line
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* Slice of structs vs. struct of slices
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* Predictability
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* Cache placement policy
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* 92 - Writing concurrent code that leads to false sharing
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* 93 - Not taking into account instruction-level parallelism
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* 94 - Not being aware of data alignment
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* 95 - Not understanding stack vs. heap
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* 96 - Not knowing how to reduce allocations
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* API change
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* Compiler optimizations
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* `sync.Pool`
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* 97 - Not relying on inlining
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* 98 - Not using Go diagnostics tooling:
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* Profiling (enabling pprof, CPU, heap, goroutines, block, and mutex profiling)
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* Execution tracer
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* 99 - Not understanding how the GC works
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* 100 - Not understanding the impacts of running Go in Docker and Kubernetes
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## Author
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Teiva Harsanyi is a senior software engineer in Docker. He has worked in various domains, including insurance, transportation, and safety-critical industries like air traffic management. He is passionate about Go and how to design and implement reliable applications.
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