feat: truncate string values and add ellipsis

[ayush3160]

This pull request introduces improvements to the handling and display of long string values in JSON diffs, especially when colorized output is involved. The main enhancement is the addition of smart truncation logic that ensures long values are presented in a readable, concise way, with ellipses indicating truncation, while preserving ANSI color formatting. This makes diffs more readable and prevents overwhelming output in the console.

String truncation and formatting improvements:

• Added the truncateStringWithEllipsis function to intelligently truncate long string values, preserving ANSI color segments and appending ellipses as needed. Supporting helpers for handling ANSI segments and truncation were also added. (jsondiff.go)
• Updated the diff output logic in the compare function to use the new truncation method for colorized differences, ensuring truncated, readable output for both expected and actual values. (jsondiff.go)
• Modified the fallback serialization of values in writeKeyValuePair to truncate long serialized values to a maximum length, improving summary readability. (jsondiff.go)

Dependency and import updates:

• Added the "unicode/utf8" import to support rune-aware string truncation. (jsondiff.go)

[keploy]

No significant code changes identified for Unit Test Generation. Please Click here to retry.

[Copilot]

Pull Request Overview

This PR adds intelligent string truncation functionality to improve readability of JSON diffs by preventing overwhelming console output when dealing with long string values. The changes implement ANSI color-aware truncation with ellipsis indicators.

• Introduces truncateStringWithEllipsis function with ANSI escape sequence handling for colorized diff output
• Updates diff comparison logic to truncate colorized string differences
• Adds fallback truncation for serialized values in writeKeyValuePair

[Copilot]

The magic number 30 should be defined as a named constant to improve maintainability and make the truncation length configurable.

Suggested change

	if len(string(serializedValue)) > 30 {
	formattedValue = string(serializedValue[:30]) + "..."
	if len(string(serializedValue)) > truncationLength {
	formattedValue = string(serializedValue[:truncationLength]) + "..."

[Copilot]

This byte-based truncation can break UTF-8 multi-byte characters, potentially causing invalid strings. Use utf8.ValidString() or implement rune-aware truncation similar to truncatePlain().

Suggested change

	if len(string(serializedValue)) > 30 {
	formattedValue = string(serializedValue[:30]) + "..."
	if utf8.RuneCountInString(formattedValue) > 30 {
	runes := []rune(formattedValue)
	formattedValue = string(runes[:30]) + "..."

[Copilot]

The magic number 20 is hardcoded in multiple places. Consider making this a configurable parameter or constant.

Suggested change

	out.WriteString(truncatePlain(val[prev:r.Start], 20, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], 20, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], 20, "..."))
	out.WriteString(truncatePlain(val[prev:r.Start], truncateLength, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], truncateLength, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], truncateLength, "..."))

[Copilot]

The magic number 20 is hardcoded in multiple places. Consider making this a configurable parameter or constant.

Suggested change

	out.WriteString(truncatePlain(val[prev:r.Start], 20, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], 20, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], 20, "..."))
	out.WriteString(truncatePlain(val[prev:r.Start], truncationLength, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], truncationLength, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], truncationLength, "..."))

[Copilot]

The magic number 20 is hardcoded in multiple places. Consider making this a configurable parameter or constant.

Suggested change

	out.WriteString(truncatePlain(val[prev:r.Start], 20, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], 20, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], 20, "..."))
	out.WriteString(truncatePlain(val[prev:r.Start], truncateLength, "..."))
	out.WriteString(truncateANSISegment(val[r.Start:r.End], truncateLength, colorEllipsis))
	prev = r.End
	}
	out.WriteString(truncatePlain(val[prev:], truncateLength, "..."))

[Sarthak160]

Instead of showing errors - ERROR failed to read the test-set report {"reportName": "test-set-10-report", "session": "test-run-26", "error": "failed to read the file: open /home/shubham/sarthak_workspace/python-mysql-big-payload-3/keploy/reports/test-run-26/test-set-10-report.yaml: no such file or directory"} we should show the test-sets selected in an array at the beginning.