Failed Test Run Error Block for React

Nothing runs. The suites, tests, values, source lines and stack lines are typed sample data in the file, and Run failed tests again waits a moment and says it did not run anything. To wire it for real, fill SUITES from your runner's report, and start the run from the button.

By a small function that takes what the two values share at their start and at their end and underlines what lies between, in both lines. The lines are printed in a monospace font with the labels the same width, so they line up character for character, and the underline is not the only cue: the lines carry a minus and a plus, and the words Expected and Received.

The same blocks, so the pane never changes size: the two lines are equal with no underline, the test's source is shown, and the stack and fix blocks say the test passed in so many milliseconds and there is nothing to fix.

Tab enters the tree on one row; the arrow keys move between rows, the side arrows open and close a suite, Home and End jump, and Enter chooses a test. The pane and the code windows in it are scroll regions with their own tab stops and names. The status line says which test is open and its result.

It rebuilds the tree with only the suites and tests that failed, so the list never has to be searched. If the test you were reading passed, the pane moves to the first failed one. Turning it off brings every test back and keeps the one chosen.

The tree sits above the pane in one scrolling column, with the Switch above the tree and the button shortened to Run failed (its name stays Run failed tests again). The long code lines scroll inside their windows, not the page.