[mathiasrw]

Closes #818

Stacked on #834.

Change

• A replacement file that can not be read now tells the reason, and shows the path as JSON, so a line break or a space at the end can be seen:

 ❌ The replacement file can not be read: "nope.txt" (ENOENT)
 ❌ The replacement file can not be read: "adir" (EISDIR)
 ❌ The replacement file can not be read: "footer.html\n" (ENOENT)

The last one is a path piped in with echo and -R, without -T. Before, all three said the same, and the last one showed a blank line.

• With --js a path that can not be read is now an error once in the run. Before it was once for each file, and in status.errors as many times.

Tests

test/fix/818.test.js is new. Two tests of --replacement-file have the new message. yarn test-ci passes.

From the review of 23 October.

After the review of 24 October

• The reason is now the text of the error, like nope.txt (ENOENT: no such file or directory), and not only the code.
• The path is shown as it is, so a Windows path like my\dir/nope.txt can be pasted back. Only a path that starts or ends with a space, or has a control char like the line break from echo, is shown as JSON, so that char can be seen: "nope.txt\n" (ENOENT: …).

After the review of 24 October

Closes #847

• The bare call at the end of the reason goes too, so EISDIR is (EISDIR: illegal operation on a directory), without , read.
• A path with a char that can not be seen is shown as JSON with that char as \u, like "no\u200bpe.txt": the C1 range, the zero-width chars, the line and paragraph separators and the marks for the direction of text. Before, only ASCII control chars and a space at the start or end were shown, so a zero-width space looked like a normal path.

Follow-up

• The regexes are made once, in re: re.unclearPath finds a space at the start or the end and the chars that can not be seen in one test, re.invisibleChars escapes the ones JSON leaves as they are, and re.fileCallInMessage is the end of the message that is told already.
• unreadable() is now pathAndReason(), with a plain if in place of the nested ternary. The output is the same.