[mathiasrw]

Closes #795

Stacked on #802.

Change

--replacement-file: the replacement is the path to a file, and the content of the file is used as the replacement.

> rexreplace '\{\{footer\}\}' partials/footer.html 'site/*.html' --replacement-file --trim-file

It is a layer of the replacement, so it combines by order:

Flags	The replacement is
--replacement-file	the content of the file at the typed path
-R --replacement-file	the content of the file at the piped path
--js --replacement-file	the content of the file at the path the code gives

> rexreplace '\{\{(\w+)\}\}' '"partials/" + $1 + ".html"' 'site/*.html' --js --replacement-file --trim-file

• $1 and $& in the content have their meaning, like a typed replacement. --literal-replacement (Add --literal-replacement to use replacement as-is to close #798 #802) uses it as it is. With --js the content is used as it is, like the value of code.
• The € and § aliases are used in the typed path, not in the content.
• Each file is read once, also when the code gives the same path for many matches.
• A file that can not be read stops the run (exit code 3) before any file is changed. With --js the path is only known when the code runs, so then it is an error once for that path, its matches are left as they are, and the run goes on (exit code 2).
• With --output-match the file is not read, and a 🟡 warning tells so.
• With --rename the content of the file is the new name.

Trimming

Flag	Trims
--trim-pipe (-T)	the piped data, as before
--trim-file	the content of the replacement file
--trim	both

They are apart, as a run can need one and not the other: when the pipe is the content and the replacement comes from a file, the file should lose its line break, but the content should come out as it came in.

Tests

yarn test-ci passes: the demo on Node and Bun (with --replacement-file), and 993 Bun tests. test/engine/replacement-file.test.js, test/engine/trim-file.test.js and test/cli/trim.test.js are new. The README has a "Templates" section.