fix(cli): validate --exclude regex pattern before use

[mvanhorn]

Summary

Added Clikt .validate {} to the --exclude option so invalid regex patterns produce a clear error instead of an unhandled exception.

Why this matters

Running ./s2c --exclude "[invalid" ... threw a PatternSyntaxException with a stack trace. Now it shows: Error: Invalid regex pattern: "[invalid". Unclosed character class near index 8.

Changes

• svg-to-compose/src/nativeMain/kotlin/Main.kt: Added .validate { } block to the exclude option (line 150) that tries constructing a Regex and calls fail() on error. Added validate import.

Testing

The validation runs at option-parsing time before any file processing begins. Invalid patterns now produce Clikt's standard error format.

Fixes #239

This contribution was developed with AI assistance (Claude Code).

Summary by CodeRabbit

• Bug Fixes
  • Improved validation for the --exclude option so invalid regular expressions are detected during command parsing, producing clearer errors and preventing invalid values from proceeding.

[coderabbitai]

No actionable comments were generated in the recent review. 🎉

ℹ️ Recent review info

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Reviewing files that changed from the base of the PR and between dc3e04a and 32f89fb.

📒 Files selected for processing (1)

• svg-to-compose/src/nativeMain/kotlin/Main.kt

---

Walkthrough

Added validation for the CLI --exclude option so the provided pattern is compiled as a regex during argument parsing; invalid patterns now cause parsing to fail with a clear error message instead of later throwing an exception.

Changes

Cohort / File(s)	Summary
CLI Option Validation svg-to-compose/src/nativeMain/kotlin/Main.kt	Added a .validate { pattern -> ... } block to the --exclude Clikt option that attempts Regex(pattern) and calls fail(...) with a user-friendly message if compilation throws, ensuring downstream code receives a valid regex or null.

Estimated code review effort

🎯 2 (Simple) | ⏱️ ~10 minutes

🚥 Pre-merge checks | ✅ 5

✅ Passed checks (5 passed)

Check name	Status	Explanation
Description Check	✅ Passed	Check skipped - CodeRabbit’s high-level summary is enabled.
Title check	✅ Passed	The title clearly and concisely describes the main change: adding validation for the --exclude regex pattern before use, which directly addresses the primary objective of the PR.
Linked Issues check	✅ Passed	The PR successfully implements the primary requirement from issue #239: validating the --exclude regex pattern at option-parsing time using Clikt's validate block and displaying a clear error message for invalid patterns.
Out of Scope Changes check	✅ Passed	All changes are directly related to validating the --exclude regex pattern as specified in issue #239. The PR does not address the additional validation gaps for --indent-size and --recursive-depth mentioned as separate concerns.
Docstring Coverage	✅ Passed	No functions found in the changed files to evaluate docstring coverage. Skipping docstring coverage check.

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✨ Finishing Touches

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[coderabbitai]

🧹 Nitpick comments (1)

svg-to-compose/src/nativeMain/kotlin/Main.kt (1)

148-157: Consider using .convert {} to avoid compiling the regex twice.

The validation block compiles the regex to check validity, then discards it. Later at line 246, the same pattern is compiled again via exclude?.let(::Regex). Using .convert {} would validate and return the Regex in a single pass.

That said, the current implementation is correct and achieves the PR objective of providing clear error messages for invalid patterns.

♻️ Optional: Single-pass validation and conversion

 private val exclude by option(
     names = arrayOf("--exclude"),
     help = "A regex used to exclude some icons from the parsing.",
-).validate { pattern ->
+).convert { pattern ->
     try {
         Regex(pattern)
     } catch (e: Exception) {
         fail("Invalid regex pattern: \"$pattern\". ${e.message}")
     }
 }

Then at line 246, simplify to:

-                    exclude = exclude?.let(::Regex),
+                    exclude = exclude,

Also applies to: 246-246

🤖 Prompt for AI Agents

Verify each finding against the current code and only fix it if needed.

In `@svg-to-compose/src/nativeMain/kotlin/Main.kt` around lines 148 - 157, The
exclude option currently uses .validate { ... } which compiles the pattern only
to check validity and then later recompiles it with exclude?.let(::Regex);
change the option to use .convert { pattern -> try { Regex(pattern) } catch (e:
Exception) { fail("Invalid regex pattern: \"$pattern\". ${e.message}") } } so
the option returns a Regex (named exclude) directly, and then remove the later
exclude?.let(::Regex) call and use exclude (or exclude?) as a Regex value
wherever referenced (e.g., the code that previously used exclude?.let(::Regex)
at the later usage).

🤖 Prompt for all review comments with AI agents

Verify each finding against the current code and only fix it if needed.

Nitpick comments:
In `@svg-to-compose/src/nativeMain/kotlin/Main.kt`:
- Around line 148-157: The exclude option currently uses .validate { ... } which
compiles the pattern only to check validity and then later recompiles it with
exclude?.let(::Regex); change the option to use .convert { pattern -> try {
Regex(pattern) } catch (e: Exception) { fail("Invalid regex pattern:
\"$pattern\". ${e.message}") } } so the option returns a Regex (named exclude)
directly, and then remove the later exclude?.let(::Regex) call and use exclude
(or exclude?) as a Regex value wherever referenced (e.g., the code that
previously used exclude?.let(::Regex) at the later usage).

---

ℹ️ Review info

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Configuration used: Path: .coderabbit.yaml

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📥 Commits

Reviewing files that changed from the base of the PR and between e1a34e0 and dc3e04a.

📒 Files selected for processing (1)

• svg-to-compose/src/nativeMain/kotlin/Main.kt

[rafaeltonholo]

Hi @mvanhorn, we should avoid using a too Generic Exception handler because it can cause problems.

Here we should be catching the PatternSyntaxException instead.

[mvanhorn]

Narrowed to IllegalArgumentException in 32f89fb. On Kotlin/Native, Regex() throws IllegalArgumentException for invalid patterns (there's no PatternSyntaxException on native targets - that's JVM-only, where it extends IllegalArgumentException). So this is the tightest catch available here.

[rafaeltonholo]

LGTM! Thanks for addressing the comment!

[mvanhorn]

Thanks for the review and merge! Glad the regex validation approach worked out.