Currently, if you have a code like:

$value = isset($number) ? $number : 0;

And your test executes it once, it'll be marked as "code executed". Even if only one of conditional statement was really executed.

Same happen on if conditionals. It'll not check if all your code was executed correctly.

if (expression1() || // executed
expression2()) // ignored (even when executed)

It can provide a false code-coverage completion, based on line execution, and not by statement execution.

Even if I separate statements in multiline, the code will be ignored as a not covered code, even if it was executed.

-- BASE SOLUTION --

I thinking about capture cursor offset when execute statement, and not by line. It'll be great if xdebug_start_code_coverage() have a new option to detail coverage.

Example result:

Line 0: <?php $number = isset($number) ? $number : 123; ?>
Line 1: <?php hello(); ?>

$coverage = [
// int line,
// int offset,
// int length,
// enum status { -1: dead code, 0: need to cover, 1: covered }

// If one of statements was not executed
// then it will results in detailed code coverage (until you cover it).
[ 0, 16, 14, 1 ], // isset($number)
[ 0, 33, 7,  1 ], // $number
[ 0, 43, 3,  0 ], // 123

// If entire line was covered, so set offset and length to 0.
// It should sounds like: entire line covered.
[ 1, 0, 0, 1 ],   // entire Line 1

];

After I fix the Line 0 else statement (covering it), results should be:

$coverage = [
[ 0, 0, 0, 1 ], // entire Line 0
[ 1, 0, 0, 1 ], // entire Line 1
];