Testing

The library's tests

The suite tests/Unit tests each tokenizer on exact expectations — every token, written {type:text} — for each language and each branch of its reading, every word of every shipped list read as its list says, the cursor and the output, the HTML and the highlighter, and the lines: their spans, numbers, ranges and annotations in every kind of comment, the line ranges and their bounds. A robustness test feeds every language sources it was not written for, checks that no byte is lost and no token is empty, nor a line lost when the block is written line by line, and reads hostile sources — ten thousand open quotes, brackets or marks — under a second each.

From the monorepo root:

vendor/bin/phpunit packages/highlight/tests

The library is held to 100 % covered mutation score by Infection; the robustness test is left out of it.

Fuzzing

Two fuzz targets read inputs nobody wrote, from the seeds of tests/Fuzz/corpus/<target>: line-ranges, whose ranges read back to themselves or are refused with InvalidLineRanges, and line-annotations, the lines of a block in five languages with their annotations read, one hl-line per line and, without annotations, the code back byte for byte. From the monorepo root:

composer fuzz -- line-ranges line-annotations

Benchmarks

HighlighterBench highlights sources of 1, 10 and 100 KB in PHP, JavaScript, HTML, CSS, YAML, Twig and SQL, and sources made of strings and comments left open; it also builds the default highlighter. The time grows with the length of the source. From the monorepo root:

composer bench -- packages/highlight/tests/Benchmark

In worker mode, tests/Worker/worker.php is a page FrankenPHP serves from one process across requests, highlighting 10 KB of PHP and 10 KB of JavaScript; the services it builds before its loop serve every request, as they do in an application's worker:

composer bench:worker phil/highlight

Testing code that highlights

The output is deterministic. Compare it exactly, or compare tokens:

self::assertSame('<span class="hl-keyword">echo</span> <span class="hl-number">1</span>', Highlighter::default()->toHtml('echo 1', 'php'));

A test of a page that shows code need not depend on the colours: check that the code's text is in it, escaped, and that the block carries its language-… class.