The snippet library.
Small, practical examples. Search by task or narrow things down below.
Handle a result with a discriminated union
Separate success data from an error message.
discriminated union✓ Tested
Handle three possible outcomes
TypeScript: Check high, normal and low values with an ordered conditional chain.
TypeScript✓ Tested
Inspect both successful and failed promise results
TypeScript: allSettled preserves input order and reports failures without rejecting the combined promise.
TypeScript✓ Tested
Inspect the parsed pieces of a URL
TypeScript: Use URL properties rather than splitting a URL at punctuation.
TypeScript✓ Tested
Iterate with array indices and values
TypeScript: entries provides each position and value without a separate counter.
TypeScript✓ Tested
Keep both matching and rejected values
TypeScript: Use two explicit outputs when a caller needs both sides of a classification.
TypeScript✓ Tested
List an object’s own enumerable keys
TypeScript: Object.keys omits inherited and non-enumerable properties.
TypeScript✓ Tested
Map items to multiple output values
TypeScript: flatMap combines mapping and a one-level flattening operation.
TypeScript✓ Tested
Measure a short text value
TypeScript: Read the length of an ASCII string. Non-ASCII text may use multiple code units or bytes depending on the language.
TypeScript✓ Tested
Name a value that stays fixed
TypeScript: Use a constant declaration or the language’s constant naming convention for a fixed limit.
TypeScript✓ Tested
Narrow a union using typeof
Handle text and numeric values with separate branches.
union✓ Tested
Normalize identifier case consistently
TypeScript: Use toLowerCase for a simple case-insensitive ASCII identifier lookup.
TypeScript✓ Tested