A set of commonly used C# extension methods that reduce boilerplate across four focused namespaces: value checks, string manipulation, collection operations, and dictionary helpers.
CSharpHelperExtensions is a lightweight NuGet package of extension methods for values, strings, enumerables, and dictionaries — designed to cut down boilerplate you'd otherwise hand-write on every project.
Most C# codebases end up with the same small helpers rewritten over and over: null-safe string checks, safe parsing, membership tests, batching, and dictionary lookups with fallbacks. Keeping these scattered across projects means copy-pasting and re-testing the same logic repeatedly.
CSharpHelperExtensions exists to centralize these common patterns into one dependency-light, well-tested package, split across four focused namespaces so you only import what you need.
Simplifies common development tasks through a comprehensive set of utility extensions for values, strings, collections, and dictionaries, reducing boilerplate code and improving consistency
| Values | In (SQL-style membership), IsBetween (four inclusive/exclusive modes), ToJson |
| Strings | 50+ null-safe, parsing, transformation, whitespace, comparison, prefix/suffix, and encoding helpers |
| Enumerable | Presence checks, materialization, async projection, partitioning, batching, conditional mutation |
| Dictionaries | Safe lookup, add-if-missing, merging, bulk add, in-place filtering, read-only views |
| Interactive samples | Four .NET Interactive notebooks covering every namespace with runnable examples |
| Layer | Technology |
|---|---|
| Language / Runtime | C# on net10.0 |
| Testing | xUnit + Shouldly |
dotnet add package CSharpHelperExtensionsImport the namespace for the extensions you need:
| Namespace | What it covers |
|---|---|
CSharpHelperExtensions.Values | In, IsBetween, ToJson |
CSharpHelperExtensions.Strings | All string extensions |
CSharpHelperExtensions.Enumerable | All IEnumerable<T> and collection extensions |
CSharpHelperExtensions.Dictionaries | All IDictionary<TKey,TValue> extensions |
The sample/ folder contains three .NET Interactive notebooks you can run directly in VS Code (with the Polyglot Notebooks extension) or Jupyter.
Before running any notebook, build the library so the DLL is available:
dotnet buildEach notebook loads the compiled DLL and imports the relevant namespace in its Setup cell — run that cell first, then run any section independently.
| Notebook | Namespace | What it covers |
|---|---|---|
sample/value-extensions.ipynb | CSharpHelperExtensions.Values | In, IsBetween (all four BetweenComparison modes), ToJson, and chaining examples |
sample/string-extensions.ipynb | CSharpHelperExtensions.Strings | All 50+ string methods grouped by category: null-safety, parsing, transformation, whitespace, comparisons, prefix/suffix, encoding, and chaining pipelines |
sample/enumerable-extension.ipynb | CSharpHelperExtensions.Enumerable | All collection methods: presence checks, materialization, async projection, partitioning, batching, conditional mutation, and chaining pipelines |
sample/dictionary-extensions.ipynb | CSharpHelperExtensions.Dictionaries | All dictionary methods: safe lookup, add-if-missing, merging, bulk add, in-place filtering, read-only views, and chaining pipelines |
usingCSharpHelperExtensions.Values;// Membership check — like SQL IN"admin".In("admin","superadmin");// trueHttpMethod.Post.In(Post,Put,Patch);// true// Range check — inclusive by default5.IsBetween(1,10);// true1.IsBetween(1,10,BetweenComparison.ExcludeBoth);// false// JSON serialisation via Newtonsoft.Jsonnew{Name="Alice",Age=30}.ToJson();// {"Name":"Alice","Age":30}new{Name="Alice"}.ToJson(indentation:true);// pretty-printedusingCSharpHelperExtensions.Strings;// Null-safety" ".IsNullOrEmpty();// true (checks whitespace)"hello".HasValue();// true((string)null).OrDefault("N/A");// "N/A"// Transformation" Hello World ".TrimToLower();// "hello world""café au lait".ToSlug();// "cafe-au-lait""4111111111111234".MaskStart(4);// "************1234"// Safe parsing — returns null instead of throwing"42".ToIntOrNull();// 42"abc".ToIntOrNull();// null// Comparisons"Hello".EqualsIgnoreCase("HELLO");// true"path/".EnsurePrefix("/");// "/path/""report.csv".TrimSuffix(".csv");// "report"// Encoding"Hello".Base64Encode();// "SGVsbG8=""Hello".ToBase64Url();// URL-safe, no padding charsusingCSharpHelperExtensions.Enumerable;// Null-safe presence checkslist.HasAny();// non-null and non-emptylist.None();// null or emptylist.OrEmpty();// null → empty sequence// Filteringitems.WhereNotNull();// removes null elementsstrings.CleanNullOrEmptyItems();// removes null, empty, and whitespace strings// Async projection with optional concurrency capvarresults=awaitids.SelectAsync(FetchAsync,maxParallel:4);// Splittingvar(passed,failed)=scores.Partition(s =>s>=60);varbatches=items.Batch(100);// process in chunks// Conditional building — fluent, returns same listvartags=newList<string>().AddIf(isPremium,"premium").AddIf(isAdmin,"admin");// Min/Max that return default instead of throwing on emptypeople.MinByOrDefault(p =>p.Age);people.MaxByOrDefault(p =>p.Age);// Utilities42.Yield();// wrap a single value as IEnumerable<T>items.WithIndex();// (Index, Item) tuplesnames.JoinAsString(", ");// fluent string.JoinusingCSharpHelperExtensions.Dictionaries;// Safe lookup — returns default instead of throwing on missing key or null dictDictionaryExtensions.GetValueOrDefault(dict,"key");// value or default(TValue)// Add-if-missing — factory only called when key is absentcache.GetOrAdd("user:1", key =>LoadFromDb(key));// existing or newly stored value// Merge two dictionaries — overwrite:false keeps existing values (default)defaults.Merge(overrides,overwrite:true);// returns same dict for chaining// Bulk add from any IEnumerable<KeyValuePair>inventory.AddRange(incomingItems);// returns same dict for chaining// Filter in-place by key predicateconfig.RemoveWhere(k =>k.StartsWith("internal."));// returns same dict for chaining// Expose as a live read-only viewIReadOnlyDictionary<string,int>view=DictionaryExtensions.AsReadOnly(dict);# Build
dotnet build
# Run all tests
dotnet test# Run tests with output
dotnet test --verbosity normal
# Run a specific test
dotnet test --filter "FullyQualifiedName~MethodName"Licensed under the MIT License.
Copyright (c) 2026 Bipin Radhakrishnan (https://github.com/rbipin/CSharpHelperExtensions)