csharp-coding-standards

Name: csharp-coding-standards
Author: wshaddix

65stars10forks

How to install csharp-coding-standards?

wshaddix/dotnet-skills/csharp-coding-standards

$npx -y skills add wshaddix/dotnet-skills --skill csharp-coding-standards

Installs into the current project.

Summary

Write modern, high-performance C# code using records, pattern matching, value objects, async/await, Span<T>/Memory<T>, and best-practice API design patterns. Emphasizes functional-style programming with C# 12+ features. Use when writing new C# code or refactoring existing code, d

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SKILL.md

1	# Modern C# Coding Standards
2
3	## When to Use This Skill
4
5	Use this skill when:
6	- Writing new C# code or refactoring existing code
7	- Designing public APIs for libraries or services
8	- Optimizing performance-critical code paths
9	- Implementing domain models with strong typing
10	- Building async/await-heavy applications
11	- Working with binary data, buffers, or high-throughput scenarios
12
13	## Core Principles
14
15	1. Immutability by Default - Use `record` types and `init`-only properties
16	2. Type Safety - Leverage nullable reference types and value objects
17	3. Modern Pattern Matching - Use `switch` expressions and patterns extensively
18	4. Async Everywhere - Prefer async APIs with proper cancellation support
19	5. Zero-Allocation Patterns - Use `Span<T>` and `Memory<T>` for performance-critical code
20	6. API Design - Accept abstractions, return appropriately specific types
21	7. Composition Over Inheritance - Avoid abstract base classes, prefer composition
22	8. Value Objects as Structs - Use `readonly record struct` for value objects
23
24	---
25
26	## Naming Conventions
27
28	### General Rules
29
30	\| Element \| Convention \| Example \|
31	\|---------\|-----------\|---------\|
32	\| Namespaces \| PascalCase, dot-separated \| `MyCompany.MyProduct.Core` \|
33	\| Classes, Records, Structs \| PascalCase \| `OrderService`, `OrderSummary` \|
34	\| Interfaces \| `I` + PascalCase \| `IOrderRepository` \|
35	\| Methods \| PascalCase \| `GetOrderAsync` \|
36	\| Properties \| PascalCase \| `OrderDate` \|
37	\| Events \| PascalCase \| `OrderCompleted` \|
38	\| Public constants \| PascalCase \| `MaxRetryCount` \|
39	\| Private fields \| `_camelCase` \| `_orderRepository` \|
40	\| Parameters, locals \| camelCase \| `orderId`, `totalAmount` \|
41	\| Type parameters \| `T` or `T` + PascalCase \| `T`, `TKey`, `TValue` \|
42	\| Enum members \| PascalCase \| `OrderStatus.Pending` \|
43
44	### Async Method Naming
45
46	Suffix async methods with `Async`:
47
48	```csharp
49	public Task<Order> GetOrderAsync(int id);
50	public ValueTask SaveChangesAsync(CancellationToken ct);
51
52	Exception: Event handlers and interface implementations where the framework does not use the `Async` suffix (e.g., ASP.NET Core middleware `InvokeAsync` is already named by the framework).
53	```
54
55	### Boolean Naming
56
57	Prefix booleans with `is`, `has`, `can`, `should`, or similar:
58
59	```csharp
60	public bool IsActive { get; set; }
61	public bool HasOrders { get; }
62	public bool CanDelete(Order order);
63	```
64
65	### Collection Naming
66
67	Use plural nouns for collections:
68
69	```csharp
70	public IReadOnlyList<Order> Orders { get; }
71	public Dictionary<string, int> CountsByName { get; }
72	```
73
74	---
75
76	## File Organization
77
78	### One Type Per File
79
80	Each top-level type (class, record, struct, interface, enum) should be in its own file, named exactly as the type. Nested types stay in the containing type's file.
81
82	```
83	OrderService.cs -> public class OrderService
84	IOrderRepository.cs -> public interface IOrderRepository
85	OrderStatus.cs -> public enum OrderStatus
86	OrderSummary.cs -> public record OrderSummary
87	```
88
89	### File-Scoped Namespaces
90
91	Always use file-scoped namespaces (C# 10+):
92
93	```csharp
94	namespace MyApp.Services;
95
96	public class OrderService { }
97	```
98
99	### Using Directives
100
101	Place `using` directives at the top of the file, outside the namespace. With `<ImplicitUsings>enable</ImplicitUsings>` (default in modern .NET), common namespaces are already imported.
102
103	Order of `using` directives:
104	1. `System.*` namespaces
105	2. Third-party namespaces
106	3. Project namespaces
107
108	---
109
110	## Code Style
111
112	### Braces
113
114	Always use braces for control flow, even for single-line bodies:
115
116	```csharp
117	if (order.IsValid)
118	{
119	Process(order);
120	}
121	```
122
123	### Expression-Bodied Members
124
125	Use expression bodies for single-expression members:
126
127	```csharp
128	public string FullName => $"{FirstName} {LastName}";
129	public override string ToString() => $"Order #{Id}";
130	```
131
132	### `var` Usage
133
134	Use `var` when the type is obvious from the right-hand side:
135
136	```csharp
137	var orders = new List<Order>();
138	var customer = GetCustomerById(id);
139
140	IOrderRepository repo = serviceProvider.GetRequiredService<IOrderRepository>();
141	decimal total = CalculateTotal(items);
142	```
143
144	### Null Handling
145
146	Prefer pattern matching over null checks:
147
148	```csharp
149	if (order is not null) { }
150	if (order is { Status: OrderStatus.Active }) { }
151
152	var name = customer?.Name ?? "Unknown";
153	var orders = customer?.Orders ?? [];
154	items ??= [];
155	```
156
157	### String Handling
158
159	Prefer string interpolation over concatenation or `string.Format`:
160
161	```csharp
162	var message = $"Order {orderId} totals {total:C2}";
163
164	var json = $$"""
165	{
166	"id": {{orderId}},
167	"n

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Type

csharp-coding-standards

65stars10forks

View on GitHub

How to install csharp-coding-standards?

wshaddix/dotnet-skills/csharp-coding-standards

$npx -y skills add wshaddix/dotnet-skills --skill csharp-coding-standards

Installs into the current project.

Summary

Files · 1

View on GitHub

SKILL.md

1	# Modern C# Coding Standards
2
3	## When to Use This Skill
4
5	Use this skill when:
6	- Writing new C# code or refactoring existing code
7	- Designing public APIs for libraries or services
8	- Optimizing performance-critical code paths
9	- Implementing domain models with strong typing
10	- Building async/await-heavy applications
11	- Working with binary data, buffers, or high-throughput scenarios
12
13	## Core Principles
14
15	1. Immutability by Default - Use `record` types and `init`-only properties
16	2. Type Safety - Leverage nullable reference types and value objects
17	3. Modern Pattern Matching - Use `switch` expressions and patterns extensively
18	4. Async Everywhere - Prefer async APIs with proper cancellation support
19	5. Zero-Allocation Patterns - Use `Span<T>` and `Memory<T>` for performance-critical code
20	6. API Design - Accept abstractions, return appropriately specific types
21	7. Composition Over Inheritance - Avoid abstract base classes, prefer composition
22	8. Value Objects as Structs - Use `readonly record struct` for value objects
23
24	---
25
26	## Naming Conventions
27
28	### General Rules
29
30	\| Element \| Convention \| Example \|
31	\|---------\|-----------\|---------\|
32	\| Namespaces \| PascalCase, dot-separated \| `MyCompany.MyProduct.Core` \|
33	\| Classes, Records, Structs \| PascalCase \| `OrderService`, `OrderSummary` \|
34	\| Interfaces \| `I` + PascalCase \| `IOrderRepository` \|
35	\| Methods \| PascalCase \| `GetOrderAsync` \|
36	\| Properties \| PascalCase \| `OrderDate` \|
37	\| Events \| PascalCase \| `OrderCompleted` \|
38	\| Public constants \| PascalCase \| `MaxRetryCount` \|
39	\| Private fields \| `_camelCase` \| `_orderRepository` \|
40	\| Parameters, locals \| camelCase \| `orderId`, `totalAmount` \|
41	\| Type parameters \| `T` or `T` + PascalCase \| `T`, `TKey`, `TValue` \|
42	\| Enum members \| PascalCase \| `OrderStatus.Pending` \|
43
44	### Async Method Naming
45
46	Suffix async methods with `Async`:
47
48	```csharp
49	public Task<Order> GetOrderAsync(int id);
50	public ValueTask SaveChangesAsync(CancellationToken ct);
51
52	Exception: Event handlers and interface implementations where the framework does not use the `Async` suffix (e.g., ASP.NET Core middleware `InvokeAsync` is already named by the framework).
53	```
54
55	### Boolean Naming
56
57	Prefix booleans with `is`, `has`, `can`, `should`, or similar:
58
59	```csharp
60	public bool IsActive { get; set; }
61	public bool HasOrders { get; }
62	public bool CanDelete(Order order);
63	```
64
65	### Collection Naming
66
67	Use plural nouns for collections:
68
69	```csharp
70	public IReadOnlyList<Order> Orders { get; }
71	public Dictionary<string, int> CountsByName { get; }
72	```
73
74	---
75
76	## File Organization
77
78	### One Type Per File
79
80	Each top-level type (class, record, struct, interface, enum) should be in its own file, named exactly as the type. Nested types stay in the containing type's file.
81
82	```
83	OrderService.cs -> public class OrderService
84	IOrderRepository.cs -> public interface IOrderRepository
85	OrderStatus.cs -> public enum OrderStatus
86	OrderSummary.cs -> public record OrderSummary
87	```
88
89	### File-Scoped Namespaces
90
91	Always use file-scoped namespaces (C# 10+):
92
93	```csharp
94	namespace MyApp.Services;
95
96	public class OrderService { }
97	```
98
99	### Using Directives
100
101	Place `using` directives at the top of the file, outside the namespace. With `<ImplicitUsings>enable</ImplicitUsings>` (default in modern .NET), common namespaces are already imported.
102
103	Order of `using` directives:
104	1. `System.*` namespaces
105	2. Third-party namespaces
106	3. Project namespaces
107
108	---
109
110	## Code Style
111
112	### Braces
113
114	Always use braces for control flow, even for single-line bodies:
115
116	```csharp
117	if (order.IsValid)
118	{
119	Process(order);
120	}
121	```
122
123	### Expression-Bodied Members
124
125	Use expression bodies for single-expression members:
126
127	```csharp
128	public string FullName => $"{FirstName} {LastName}";
129	public override string ToString() => $"Order #{Id}";
130	```
131
132	### `var` Usage
133
134	Use `var` when the type is obvious from the right-hand side:
135
136	```csharp
137	var orders = new List<Order>();
138	var customer = GetCustomerById(id);
139
140	IOrderRepository repo = serviceProvider.GetRequiredService<IOrderRepository>();
141	decimal total = CalculateTotal(items);
142	```
143
144	### Null Handling
145
146	Prefer pattern matching over null checks:
147
148	```csharp
149	if (order is not null) { }
150	if (order is { Status: OrderStatus.Active }) { }
151
152	var name = customer?.Name ?? "Unknown";
153	var orders = customer?.Orders ?? [];
154	items ??= [];
155	```
156
157	### String Handling
158
159	Prefer string interpolation over concatenation or `string.Format`:
160
161	```csharp
162	var message = $"Order {orderId} totals {total:C2}";
163
164	var json = $$"""
165	{
166	"id": {{orderId}},
167	"n

People who liked this also viewed

6 picks

Type