HHH-19969 - Fix and test for error in camel to snake case conversion

[jrenaat]

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https://hibernate.atlassian.net/browse/HHH-19969

[beikov]

It seems to me that this would be simpler and avoid creating the char array copy.

Suggested change

	final char[] copy = builder.toString().toCharArray();
	int builderIndex = 1;
	for ( int i = 1; i <= copy.length - 1; i++ ) {
	if ( isUnderscoreRequired(
	copy[i - 1],
	copy[i],
	i == copy.length - 1 ? '*' : copy[i + 1] ) // add some fictitious final character
	) {
	builder.insert( builderIndex++, '_' );
	}
	builderIndex++;
	}
	for ( int i = 1; i < builder.length() - 1; i++ ) {
	if ( isUnderscoreRequired( builder.charAt( i - 1 ), builder.charAt( i ), builder.charAt( i + 1 ) ) ) {
	builder.insert( i++, '_' );
	}
	}
	if ( builder.length() > 1 && isUnderscoreRequired( builder.charAt(builder.length() - 2), builder.charAt(builder.length() - 1), '0' ) ) {
	builder.insert( builder.length() - 1, '_' );
	}

[jrenaat]

I used the char[] copy to avoid the index increment inside the for loop, which is what caused the jump over the last character (and it makes it somewhat hard to follow, and it's imo ugly (arguable))
Also, your change still uses the copy ?

[beikov]

Also, your change still uses the copy ?

Yeah, forgot to adapt a copy pasted part.

I used the char[] copy to avoid the index increment inside the for loop, which is what caused the jump over the last character (and it makes it somewhat hard to follow, and it's imo ugly (arguable))

Dunno if it's "ugly", but let's focus on the bug at hand. It seems to me that the problem is/was rather that the last character of the string was not properly considered, and just checking the last character as "current" character is the way to go to understand if an underscore is needed. Am I wrong?