[Bug]: MigrationTester.FixerSetup never applies computed maxVersion to builder

[Splatcrafter]

AI REVIEWED

Module: testkit
File: testkit/harness/MigrationTester.java (~line 306, 340)
Severity: High

Summary

FixerSetup initializes the DataFixerBuilder with Integer.MAX_VALUE as a placeholder current version and tracks maxVersion during addFix() calls. However, the builder is built with the original Integer.MAX_VALUE — the computed maxVersion is never applied.

Expected Behavior

The fixer should be built with the actual maximum version derived from the registered fixes.

Actual Behavior

// Line 306: Placeholder version
private final DataFixerBuilder builder = new DataFixerBuilder(new DataVersion(Integer.MAX_VALUE));
private int maxVersion = 0; // tracked but never used

// Line 340: Built with Integer.MAX_VALUE still
return this.builder.build();

Suggested Fix

Update the builder version before building, or initialize with the computed max:

public DataFixer build() {
    // Apply computed maxVersion before building
    return new DataFixerBuilder(new DataVersion(this.maxVersion))
        // re-register fixes...
        .build();
}

Or restructure to pass maxVersion at construction time.