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Eric Sunshine 0d7131763e chainlint.sed: drop unnecessary distinction between ?!AMP?! and ?!SEMI?!
>From inception, when chainlint.sed encountered a line using semicolon to
separate commands rather than `&&`, it would insert a ?!SEMI?!
annotation at the beginning of the line rather ?!AMP?! even though the
&&-chain is also broken by the semicolon. Given a line such as:

    ?!SEMI?! cmd1; cmd2 &&

the ?!SEMI?! annotation makes it easier to see what the problem is than
if the output had been:

    ?!AMP?! cmd1; cmd2 &&

which might confuse the test author into thinking that the linter is
broken (since the line clearly ends with `&&`).

However, now that the ?!AMP?! an ?!SEMI?! annotations are inserted at
the point of breakage rather than at the beginning of the line, and
taking into account that both represent a broken &&-chain, there is
little reason to distinguish between the two. Using ?!AMP?! alone is
sufficient to point the test author at the problem. For instance, in:

    cmd1; ?!AMP?! cmd2 &&
    cmd3

it is clear that the &&-chain is broken between `cmd1` and `cmd2`.
Likewise, in:

    cmd1 && cmd2 ?!AMP?!
    cmd3

it is clear that the &&-chain is broken between `cmd2` and `cmd3`.
Finally, in:

    cmd1; ?!AMP?! cmd2 ?!AMP?!
    cmd3

it is clear that the &&-chain is broken between each command.

Hence, there is no longer a good reason to make a distinction between a
broken &&-chain due to a semicolon and a broken chain due to a missing
`&&` at end-of-line. Therefore, drop the ?!SEMI?! annotation and use
?!AMP?! exclusively.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13 14:15:29 -08:00
Eric Sunshine fbd992b61b chainlint.sed: improve ?!SEMI?! placement accuracy
When chainlint.sed detects commands separated by a semicolon rather than
by `&&`, it places a ?!SEMI?! annotation at the beginning of the line.
However, this is an unusual location for programmers accustomed to error
messages (from compilers, for instance) indicating the exact point of
the problem. Therefore, relocate the ?!SEMI?! annotation to the location
of the semicolon in order to better direct the programmer's attention to
the source of the problem.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2021-12-13 14:15:29 -08:00
Eric Sunshine 90a880393a t/chainlint: add chainlint "one-liner" test cases
The --chain-lint option uses heuristics and knowledge of shell syntax to
detect broken &&-chains in subshells by pure textual inspection. The
heuristics handle a range of stylistic variations in existing tests
(evolved over the years), however, they are still best-guesses. As such,
it is possible for future changes to accidentally break assumptions upon
which the heuristics are based. Protect against this possibility by
adding tests which check the linter itself for correctness.

In addition to protecting against regressions, these tests help document
(for humans) expected behavior, which is important since the linter's
implementation language ('sed') does not necessarily lend itself to easy
comprehension.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
2018-07-17 09:15:14 -07:00