TruncationConfig

TruncationConfig controls how large collections are truncated when rendering, allowing you to limit output size and choose which elements to display.

Table of Contents

Properties

Property Type Default Description
MaxCollectionCount int? null Maximum number of collection items to display. null means no limit.
Mode TruncationMode Head How to truncate: Head, Tail, or HeadAndTail
PerDimension bool true Apply truncation per dimension for multi-dimensional arrays

TruncationMode

The Mode property controls which elements are shown when truncation occurs:

Mode Description Example (MaxCollectionCount = 4)
Head Show first N elements 1, 2, 3, 4, [... 6 more]
Tail Show last N elements [... 6 more], 7, 8, 9, 10
HeadAndTail Show first N/2 and last N/2 1, 2, [... 6 more], 9, 10

Examples

Basic Truncation

Limit the number of items displayed from large collections:

var largeArray = Enumerable.Range(1, 100).ToArray();

// Only show first 10 items
largeArray.Dump(truncationConfig: new TruncationConfig { MaxCollectionCount = 10 });
// Output: 1, 2, 3, 4, 5, 6, 7, 8, 9, 10, [... 90 more]

Tail Truncation

Show the last N elements instead of the first:

var numbers = Enumerable.Range(1, 20).ToArray();

numbers.Dump(truncationConfig: new TruncationConfig 
{ 
    MaxCollectionCount = 5, 
    Mode = TruncationMode.Tail 
});
// Output: [... 15 more], 16, 17, 18, 19, 20

Head and Tail Truncation

Show elements from both ends with truncation in the middle:

var numbers = Enumerable.Range(1, 20).ToArray();

numbers.Dump(truncationConfig: new TruncationConfig 
{ 
    MaxCollectionCount = 6, 
    Mode = TruncationMode.HeadAndTail 
});
// Output: 1, 2, 3, [... 14 more], 19, 20

Multi-Dimensional Arrays

By default, truncation is applied per dimension:

var matrix = new int[10, 10];
// Fill matrix...

// Truncate both rows and columns
matrix.Dump(truncationConfig: new TruncationConfig { MaxCollectionCount = 3 });
// Shows 3x3 grid with truncation markers for remaining rows/columns

To truncate only the total count (flattened):

matrix.Dump(truncationConfig: new TruncationConfig 
{ 
    MaxCollectionCount = 10, 
    PerDimension = false 
});

Global Configuration

Set truncation globally for all dumps:

// Limit all collections to 50 items by default
DumpConfig.Default.TruncationConfig.MaxCollectionCount = 50;

// Use HeadAndTail mode globally
DumpConfig.Default.TruncationConfig.Mode = TruncationMode.HeadAndTail;

// All dumps now use these settings
myLargeCollection.Dump();

Complete Truncation Configuration 

var truncationConfig = new TruncationConfig
{
    MaxCollectionCount = 20,
    Mode = TruncationMode.HeadAndTail,
    PerDimension = true
};

largeCollection.Dump(truncationConfig: truncationConfig);

Use Cases

Debugging Large Data Sets

When working with large collections, truncation prevents overwhelming output:

// Database query results
var users = database.GetAllUsers(); // Returns 10,000 records

// Show just enough to verify the query
users.Dump(truncationConfig: new TruncationConfig { MaxCollectionCount = 10 });

Log Files and CI Output

For log output where space is limited:

// Compact truncation for logs
DumpConfig.Default.TruncationConfig.MaxCollectionCount = 5;
DumpConfig.Default.TruncationConfig.Mode = TruncationMode.HeadAndTail;

API Response Inspection

When debugging API responses with large arrays:

var response = await httpClient.GetFromJsonAsync<ApiResponse>(url);

// See start and end of data
response.Items.Dump(truncationConfig: new TruncationConfig 
{ 
    MaxCollectionCount = 10, 
    Mode = TruncationMode.HeadAndTail 
});

Memory-Efficient Debugging

Truncation is memory-efficient - elements beyond the limit are not stored or processed:

// Safe to dump large IEnumerables
GetMillionsOfItems()
    .Dump(truncationConfig: new TruncationConfig { MaxCollectionCount = 100 });
// Only first 100 items are enumerated

Truncation Message Format

When truncation occurs, a marker is displayed showing how many items were truncated:

  • Default format: [... N more] - e.g., [... 990 more]
  • Compact format: [... +N] - Used in table headers for multi-dimensional arrays

See Also