chainlint: make error messages self-explanatory

The annotations emitted by chainlint to indicate detected problems are
overly terse, so much so that developers new to the project -- those who
should most benefit from the linting -- may find them baffling. For
instance, although the author of chainlint and seasoned Git developers
may understand that "?!AMP?!" is an abbreviation of "ampersand" and
indicates a break in the &&-chain, this may not be obvious to newcomers.

The "?!LOOP?!" case is particularly serious because that terse single
word does nothing to convey that the loop body should end with
"|| return 1" (or "|| exit 1" in a subshell) to ensure that a failing
command in the body aborts the loop immediately. Moreover, unlike
&&-chaining which is ubiquitous in Git tests, the "|| return 1" idiom is
relatively infrequent, thus may be harder for a newcomer to discover by
consulting nearby code.

Address these shortcomings by emitting human-readable messages which
both explain the problem and give a strong hint about how to correct it.

Signed-off-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
maint
Eric Sunshine 2024-09-10 00:10:12 -04:00 committed by Junio C Hamano
parent 588ef84ece
commit e44f15ba3e
44 changed files with 104 additions and 90 deletions

View File

@ -9,9 +9,9 @@
# Input arguments are pathnames of shell scripts containing test definitions,
# or globs referencing a collection of scripts. For each problem discovered,
# the pathname of the script containing the test is printed along with the test
# name and the test body with a `?!FOO?!` annotation at the location of each
# detected problem, where "FOO" is a tag such as "AMP" which indicates a broken
# &&-chain. Returns zero if no problems are discovered, otherwise non-zero.
# name and the test body with a `?!LINT: ...?!` annotation at the location of
# each detected problem, where "..." is an explanation of the problem. Returns
# zero if no problems are discovered, otherwise non-zero.

use warnings;
use strict;
@ -181,7 +181,7 @@ sub swallow_heredocs {
$self->{lineno} += () = $body =~ /\n/sg;
next;
}
push(@{$self->{parser}->{problems}}, ['UNCLOSED-HEREDOC', $tag]);
push(@{$self->{parser}->{problems}}, ['HEREDOC', $tag]);
$$b =~ /(?:\G|\n).*\z/gc; # consume rest of input
my $body = substr($$b, $start, pos($$b) - $start);
$self->{lineno} += () = $body =~ /\n/sg;
@ -238,6 +238,7 @@ sub new {
stop => [],
output => [],
heredocs => {},
insubshell => 0,
} => $class;
$self->{lexer} = Lexer->new($self, $s);
return $self;
@ -296,8 +297,11 @@ sub parse_group {

sub parse_subshell {
my $self = shift @_;
return ($self->parse(qr/^\)$/),
$self->expect(')'));
$self->{insubshell}++;
my @tokens = ($self->parse(qr/^\)$/),
$self->expect(')'));
$self->{insubshell}--;
return @tokens;
}

sub parse_case_pattern {
@ -528,7 +532,7 @@ sub parse_loop_body {
return @tokens if ends_with(\@tokens, [qr/^\|\|$/, "\n", qr/^echo$/, qr/^.+$/]);
# flag missing "return/exit" handling explicit failure in loop body
my $n = find_non_nl(\@tokens);
push(@{$self->{problems}}, ['LOOP', $tokens[$n]]);
push(@{$self->{problems}}, [$self->{insubshell} ? 'LOOPEXIT' : 'LOOPRETURN', $tokens[$n]]);
return @tokens;
}

@ -620,6 +624,15 @@ sub unwrap {
return $s
}

sub format_problem {
local $_ = shift;
/^AMP$/ && return "missing '&&'";
/^LOOPRETURN$/ && return "missing '|| return 1'";
/^LOOPEXIT$/ && return "missing '|| exit 1'";
/^HEREDOC$/ && return 'unclosed heredoc';
die("unrecognized problem type '$_'\n");
}

sub check_test {
my $self = shift @_;
my $title = unwrap(shift @_);
@ -643,9 +656,10 @@ sub check_test {
for (sort {$a->[1]->[2] <=> $b->[1]->[2]} @$problems) {
my ($label, $token) = @$_;
my $pos = $token->[2];
my $err = format_problem($label);
$checked .= substr($body, $start, $pos - $start);
$checked .= ' ' unless $checked =~ /\s$/;
$checked .= "$c->{rev}$c->{red}?!$label?!$c->{reset}";
$checked .= "$c->{rev}$c->{red}?!LINT: $err?!$c->{reset}";
$checked .= ' ' unless $pos >= length($body) ||
substr($body, $pos, 1) =~ /^\s/;
$start = $pos;

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@ -4,6 +4,6 @@
5 baz
6 ) &&
7 (
8 bar=$((42 + 1)) ?!AMP?!
8 bar=$((42 + 1)) ?!LINT: missing '&&'?!
9 baz
10 )

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@ -1,20 +1,20 @@
2 (
3 foo &&
4 {
5 echo a ?!AMP?!
5 echo a ?!LINT: missing '&&'?!
6 echo b
7 } &&
8 bar &&
9 {
10 echo c
11 } ?!AMP?!
11 } ?!LINT: missing '&&'?!
12 baz
13 ) &&
14
15 {
16 echo a; ?!AMP?! echo b
16 echo a; ?!LINT: missing '&&'?! echo b
17 } &&
18 { echo a; ?!AMP?! echo b; } &&
18 { echo a; ?!LINT: missing '&&'?! echo b; } &&
19
20 {
21 echo "${var}9" &&

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@ -1,6 +1,6 @@
2 (
3 foo &&
4 bar ?!AMP?!
4 bar ?!LINT: missing '&&'?!
5 baz &&
6 wop
7 )

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@ -9,11 +9,11 @@
10 case "$x" in
11 x) foo ;;
12 *) bar ;;
13 esac ?!AMP?!
13 esac ?!LINT: missing '&&'?!
14 foobar
15 ) &&
16 (
17 case "$x" in 1) true;; esac &&
18 case "$y" in 2) false;; esac ?!AMP?!
18 case "$y" in 2) false;; esac ?!LINT: missing '&&'?!
19 foobar
20 )

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@ -4,6 +4,6 @@
5 echo failed!
6 false
7 else
8 echo it went okay ?!AMP?!
8 echo it went okay ?!LINT: missing '&&'?!
9 congratulate user
10 fi

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@ -1,5 +1,5 @@
2 echo nobody home && {
3 test the doohicky ?!AMP?!
3 test the doohicky ?!LINT: missing '&&'?!
4 right now
5 } &&
6

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@ -1,10 +1,10 @@
2 mkdir sub && (
3 cd sub &&
4 foo the bar ?!AMP?!
4 foo the bar ?!LINT: missing '&&'?!
5 nuff said
6 ) &&
7
8 cut "-d " -f actual | (read s1 s2 s3 &&
9 test -f $s1 ?!AMP?!
9 test -f $s1 ?!LINT: missing '&&'?!
10 test $(cat $s2) = tree2path1 &&
11 test $(cat $s3) = tree3path1)

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@ -4,6 +4,6 @@
5 baz
6 ) &&
7 (
8 bar=$(gobble blocks) ?!AMP?!
8 bar=$(gobble blocks) ?!LINT: missing '&&'?!
9 baz
10 )

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@ -4,6 +4,6 @@
5 :
6 else
7 echo >file
8 fi ?!LOOP?!
8 fi ?!LINT: missing '|| exit 1'?!
9 done) &&
10 test ! -f file

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@ -2,7 +2,7 @@
3 bar
4 ) &&
5
6 (cd foo ?!AMP?!
6 (cd foo ?!LINT: missing '&&'?!
7 bar
8 ) &&
9
@ -13,5 +13,5 @@
14 (cd foo &&
15 bar) &&
16
17 (cd foo ?!AMP?!
17 (cd foo ?!LINT: missing '&&'?!
18 bar)

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@ -1,14 +1,14 @@
2 (
3 for i in a b c
4 do
5 echo $i ?!AMP?!
6 cat <<-\EOF ?!LOOP?!
5 echo $i ?!LINT: missing '&&'?!
6 cat <<-\EOF ?!LINT: missing '|| exit 1'?!
7 bar
8 EOF
9 done ?!AMP?!
9 done ?!LINT: missing '&&'?!
10
11 for i in a b c; do
12 echo $i &&
13 cat $i ?!LOOP?!
13 cat $i ?!LINT: missing '|| exit 1'?!
14 done
15 )

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@ -4,8 +4,8 @@
5
6 remove_object() {
7 file=$(sha1_file "$*") &&
8 test -e "$file" ?!AMP?!
8 test -e "$file" ?!LINT: missing '&&'?!
9 rm -f "$file"
10 } ?!AMP?!
10 } ?!LINT: missing '&&'?!
11
12 sha1_file arg && remove_object arg

View File

@ -1,2 +1,2 @@
2 echo "we should find this" ?!AMP?!
2 echo "we should find this" ?!LINT: missing '&&'?!
3 echo "even though our heredoc has its indent stripped"

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@ -1,7 +1,7 @@
2 echo "outer here-doc does not allow indented end-tag" ?!AMP?!
2 echo "outer here-doc does not allow indented end-tag" ?!LINT: missing '&&'?!
3 cat >file <<-\EOF &&
4 but this inner here-doc
5 does allow indented EOF
6 EOF
7 echo "missing chain after" ?!AMP?!
7 echo "missing chain after" ?!LINT: missing '&&'?!
8 echo "but this line is OK because it's the end"

View File

@ -1,7 +1,7 @@
2 echo "missing chain before" ?!AMP?!
2 echo "missing chain before" ?!LINT: missing '&&'?!
3 cat >file <<-\EOF &&
4 inside inner here-doc
5 these are not shell commands
6 EOF
7 echo "missing chain after" ?!AMP?!
7 echo "missing chain after" ?!LINT: missing '&&'?!
8 echo "but this line is OK because it's the end"

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@ -1,2 +1,2 @@
8 echo "actual test commands" ?!AMP?!
8 echo "actual test commands" ?!LINT: missing '&&'?!
9 echo "that should be checked"

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@ -4,7 +4,7 @@
5 chunks: oid_fanout oid_lookup commit_metadata generation_data bloom_indexes bloom_data
6 EOF
7
8 cat >expect << -EOF ?!AMP?!
8 cat >expect << -EOF ?!LINT: missing '&&'?!
9 this is not indented
10 -EOF
11

View File

@ -3,6 +3,6 @@
4 fossil
5 vegetable
6 END
7 wiffle) ?!AMP?!
7 wiffle) ?!LINT: missing '&&'?!
8 echo $x
9 )

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@ -1,6 +1,6 @@
2 (
3 cat <<-\TXT && echo "multi-line
4 string" ?!AMP?!
4 string" ?!LINT: missing '&&'?!
5 fizzle
6 TXT
7 bap

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@ -2,6 +2,6 @@
3 marcia ||
4 kevin
5 then
6 echo "nomads" ?!AMP?!
6 echo "nomads" ?!LINT: missing '&&'?!
7 echo "for sure"
8 fi

View File

@ -5,8 +5,8 @@
6 then
7 echo "err"
8 exit 1
9 fi ?!AMP?!
9 fi ?!LINT: missing '&&'?!
10 foo
11 done ?!AMP?!
11 done ?!LINT: missing '&&'?!
12 bar
13 )

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@ -1,7 +1,7 @@
2 (
3 if test -n ""
4 then
5 echo very ?!AMP?!
5 echo very ?!LINT: missing '&&'?!
6 echo empty
7 elif test -z ""
8 then
@ -11,7 +11,7 @@
12 cat <<-\EOF
13 bar
14 EOF
15 fi ?!AMP?!
15 fi ?!LINT: missing '&&'?!
16 echo poodle
17 ) &&
18 (

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@ -1,6 +1,6 @@
2 (
3 foobar && # comment 1
4 barfoo ?!AMP?! # wrong position for &&
4 barfoo ?!LINT: missing '&&'?! # wrong position for &&
5 flibble "not a # comment"
6 ) &&
7

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@ -11,5 +11,5 @@
12 do
13 printf "%"$n"s" X > r2/large.$n &&
14 git -C r2 add large.$n &&
15 git -C r2 commit -m "$n" ?!LOOP?!
15 git -C r2 commit -m "$n" ?!LINT: missing '|| return 1'?!
16 done

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@ -3,10 +3,10 @@
4 then
5 while true
6 do
7 echo "pop" ?!AMP?!
8 echo "glup" ?!LOOP?!
9 done ?!AMP?!
7 echo "pop" ?!LINT: missing '&&'?!
8 echo "glup" ?!LINT: missing '|| exit 1'?!
9 done ?!LINT: missing '&&'?!
10 foo
11 fi ?!AMP?!
11 fi ?!LINT: missing '&&'?!
12 bar
13 )

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@ -3,7 +3,7 @@
4 line 2
5 line 3" &&
6 y="line 1
7 line2" ?!AMP?!
7 line2" ?!LINT: missing '&&'?!
8 foobar
9 ) &&
10 (

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@ -1,5 +1,5 @@
2 ! (foo && bar) &&
3 ! (foo && bar) >baz &&
4
5 ! (foo; ?!AMP?! bar) &&
6 ! (foo; ?!AMP?! bar) >baz
5 ! (foo; ?!LINT: missing '&&'?! bar) &&
6 ! (foo; ?!LINT: missing '&&'?! bar) >baz

View File

@ -5,7 +5,7 @@
6
7 (cd foo &&
8 bar
9 ) ?!AMP?!
9 ) ?!LINT: missing '&&'?!
10
11 (
12 cd foo &&
@ -13,13 +13,13 @@
14
15 (
16 cd foo &&
17 bar) ?!AMP?!
17 bar) ?!LINT: missing '&&'?!
18
19 (cd foo &&
20 bar) &&
21
22 (cd foo &&
23 bar) ?!AMP?!
23 bar) ?!LINT: missing '&&'?!
24
25 foobar
26 )

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@ -18,7 +18,7 @@
19 toink
20 INPUT_END
21
22 cat <<-\EOT ?!AMP?!
22 cat <<-\EOT ?!LINT: missing '&&'?!
23 text goes here
24 data <<EOF
25 data goes here

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@ -2,8 +2,8 @@
3 do
4 for j in 0 1 2 3 4 5 6 7 8 9;
5 do
6 echo "$i$j" >"path$i$j" ?!LOOP?!
7 done ?!LOOP?!
6 echo "$i$j" >"path$i$j" ?!LINT: missing '|| return 1'?!
7 done ?!LINT: missing '|| return 1'?!
8 done &&
9
10 for i in 0 1 2 3 4 5 6 7 8 9;
@ -18,7 +18,7 @@
19 do
20 for j in 0 1 2 3 4 5 6 7 8 9;
21 do
22 echo "$i$j" >"path$i$j" ?!LOOP?!
22 echo "$i$j" >"path$i$j" ?!LINT: missing '|| return 1'?!
23 done || return 1
24 done &&
25

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@ -6,6 +6,6 @@
7 # minor numbers of cows (or do they?)
8 baz &&
9 snaff
10 ) ?!AMP?!
10 ) ?!LINT: missing '&&'?!
11 fuzzy
12 )

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@ -7,7 +7,7 @@
8
9 cd foo &&
10 (
11 echo a ?!AMP?!
11 echo a ?!LINT: missing '&&'?!
12 echo b
13 ) >file
14 )

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@ -9,6 +9,6 @@
10 echo ourside &&
11 echo "=======" &&
12 echo theirside &&
13 echo ">>>>>>> theirs" ?!AMP?!
13 echo ">>>>>>> theirs" ?!LINT: missing '&&'?!
14 poodle
15 ) >merged

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@ -3,7 +3,7 @@
4 cd dir-rename-and-content &&
5 test_write_lines 1 2 3 4 5 >foo &&
6 mkdir olddir &&
7 for i in a b c; do echo $i >olddir/$i; ?!LOOP?! done ?!AMP?!
7 for i in a b c; do echo $i >olddir/$i; ?!LINT: missing '|| exit 1'?! done ?!LINT: missing '&&'?!
8 git add foo olddir &&
9 git commit -m "original" &&
10 )

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@ -2,8 +2,8 @@
3 (foo && bar) |
4 (foo && bar) >baz &&
5
6 (foo; ?!AMP?! bar) &&
7 (foo; ?!AMP?! bar) |
8 (foo; ?!AMP?! bar) >baz &&
6 (foo; ?!LINT: missing '&&'?! bar) &&
7 (foo; ?!LINT: missing '&&'?! bar) |
8 (foo; ?!LINT: missing '&&'?! bar) >baz &&
9
10 (foo "bar; baz")

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@ -4,7 +4,7 @@
5 baz &&
6
7 fish |
8 cow ?!AMP?!
8 cow ?!LINT: missing '&&'?!
9
10 sunder
11 )

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@ -1,19 +1,19 @@
2 (
3 cat foo ; ?!AMP?! echo bar ?!AMP?!
4 cat foo ; ?!AMP?! echo bar
3 cat foo ; ?!LINT: missing '&&'?! echo bar ?!LINT: missing '&&'?!
4 cat foo ; ?!LINT: missing '&&'?! echo bar
5 ) &&
6 (
7 cat foo ; ?!AMP?! echo bar &&
8 cat foo ; ?!AMP?! echo bar
7 cat foo ; ?!LINT: missing '&&'?! echo bar &&
8 cat foo ; ?!LINT: missing '&&'?! echo bar
9 ) &&
10 (
11 echo "foo; bar" &&
12 cat foo; ?!AMP?! echo bar
12 cat foo; ?!LINT: missing '&&'?! echo bar
13 ) &&
14 (
15 foo;
16 ) &&
17 (cd foo &&
18 for i in a b c; do
19 echo; ?!LOOP?!
19 echo; ?!LINT: missing '|| exit 1'?!
20 done)

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@ -6,7 +6,7 @@
7 nevermore...
8 EOF
9
10 cat <<EOF >bip ?!AMP?!
10 cat <<EOF >bip ?!LINT: missing '&&'?!
11 fish fly high
12 EOF
13

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@ -3,17 +3,17 @@
4 (foo && bar) |
5 (foo && bar) >baz &&
6
7 (foo; ?!AMP?! bar) &&
8 (foo; ?!AMP?! bar) |
9 (foo; ?!AMP?! bar) >baz &&
7 (foo; ?!LINT: missing '&&'?! bar) &&
8 (foo; ?!LINT: missing '&&'?! bar) |
9 (foo; ?!LINT: missing '&&'?! bar) >baz &&
10
11 (foo || exit 1) &&
12 (foo || exit 1) |
13 (foo || exit 1) >baz &&
14
15 (foo && bar) ?!AMP?!
15 (foo && bar) ?!LINT: missing '&&'?!
16
17 (foo && bar; ?!AMP?! baz) ?!AMP?!
17 (foo && bar; ?!LINT: missing '&&'?! baz) ?!LINT: missing '&&'?!
18
19 foobar
20 )

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@ -2,13 +2,13 @@
3 git config filter.rot13.clean ./rot13.sh &&
4
5 {
6 echo "*.t filter=rot13" ?!AMP?!
6 echo "*.t filter=rot13" ?!LINT: missing '&&'?!
7 echo "*.i ident"
8 } >.gitattributes &&
9
10 {
11 echo a b c d e f g h i j k l m ?!AMP?!
12 echo n o p q r s t u v w x y z ?!AMP?!
11 echo a b c d e f g h i j k l m ?!LINT: missing '&&'?!
12 echo n o p q r s t u v w x y z ?!LINT: missing '&&'?!
13 echo '$Id$'
14 } >test &&
15 cat test >test.t &&
@ -19,7 +19,7 @@
20 git checkout -- test test.t test.i &&
21
22 echo "content-test2" >test2.o &&
23 echo "content-test3 - filename with special characters" >"test3 'sq',$x=.o" ?!AMP?!
23 echo "content-test3 - filename with special characters" >"test3 'sq',$x=.o" ?!LINT: missing '&&'?!
24
25 downstream_url_for_sed=$(
26 printf "%sn" "$downstream_url" |

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@ -1,4 +1,4 @@
2 command_which_is_run &&
3 cat >expect <<-\EOF ?!UNCLOSED-HEREDOC?! &&
3 cat >expect <<-\EOF ?!LINT: unclosed heredoc?! &&
4 we forget to end the here-doc
5 command_which_is_gobbled

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@ -1,5 +1,5 @@
2 command_which_is_run &&
3 cat >expect <<\EOF ?!UNCLOSED-HEREDOC?! &&
3 cat >expect <<\EOF ?!LINT: unclosed heredoc?! &&
4 we try to end the here-doc below,
5 but the indentation throws us off
6 since the operator is not "<<-".

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@ -1,14 +1,14 @@
2 (
3 while true
4 do
5 echo foo ?!AMP?!
6 cat <<-\EOF ?!LOOP?!
5 echo foo ?!LINT: missing '&&'?!
6 cat <<-\EOF ?!LINT: missing '|| exit 1'?!
7 bar
8 EOF
9 done ?!AMP?!
9 done ?!LINT: missing '&&'?!
10
11 while true; do
12 echo foo &&
13 cat bar ?!LOOP?!
13 cat bar ?!LINT: missing '|| exit 1'?!
14 done
15 )