env: fix errors on valid interpolation expressions #307
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milas
commented
Sep 23, 2022
| func TestInvalid(t *testing.T) { | ||
| invalidTemplates := []string{ | ||
| "${", | ||
| "$}", |
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This is valid and is in the new test cases above.
❯ echo "$}"
$}
|
@milas can you sign-off your commit please 😂 ? |
milas
commented
Sep 23, 2022
| @@ -31,7 +31,7 @@ var substitutionNamed = "[_a-z][_a-z0-9]*" | |||
| var substitutionBraced = "[_a-z][_a-z0-9]*(?::?[-+?](.*}|[^}]*))?" | |||
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| var patternString = fmt.Sprintf( | |||
| "%s(?i:(?P<escaped>%s)|(?P<named>%s)|{(?P<braced>%s)}|(?P<invalid>))", | |||
| "%s(?i:(?P<escaped>%s)|(?P<named>%s)|{(?:(?P<braced>%s)}|(?P<invalid>)))", | |||
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Here's a playground with the expanded regex and various cases: https://regex101.com/r/H5aQT8/1
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The change here is to move the "invalid" named group (doesn't actually capture anything, used as a sentinel) to be part of the "braced" section so we can detect an unmatched brace, so there's an extra (non-capturing) group.
The parser was too strict here and would reject valid constructs
that used an unescaped `$` that was not part of a variable
expression (and not ambiguous).
Now, only errors for unmatched braced expressions (e.g. `${FOO`)
are returned, but other valid cases are ignored and the `$` will
be treated literally, e.g. `a $ string` -> `a $ string`, which is
the same as in POSIX.
Signed-off-by: Milas Bowman <milas.bowman@docker.com>
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nicksieger
approved these changes
Sep 23, 2022
|
Awesome! |
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The parser was too strict here and would reject valid constructs that used an unescaped
$that was not part of a variable expression (and not ambiguous).Now, only errors for unmatched braced expressions (e.g.
${FOO) are returned, but other valid cases are ignored and the$will be treated literally, e.g.a $ string->a $ string, which is the same as in POSIX.