test-drawdag: add a test for drawdag.py
The drawdag script is useful but does not have a formal test. This patch
adds it.
$ cat >> $HGRCPATH<<EOF
> [extensions]
> drawdag=$TESTDIR/drawdag.py
> EOF
$ reinit () {
> rm -rf .hg && hg init
> }
$ hg init
Test what said in drawdag.py docstring
$ hg debugdrawdag <<'EOS'
> c d
> |/
> b
> |
> a
> EOS
$ hg log -G -T '{rev} {desc} ({tags})'
o 3 d (d tip)
|
| o 2 c (c)
|/
o 1 b (b)
|
o 0 a (a)
$ hg debugdrawdag <<'EOS'
> foo bar bar foo
> | / | |
> ancestor(c,d) a baz
> EOS
$ hg log -G -T '{desc}'
o foo
|\
+---o bar
| | |
| o | baz
| /
+---o d
| |
+---o c
| |
o | b
|/
o a
$ reinit
$ hg debugdrawdag <<'EOS'
> o foo
> |\
> +---o bar
> | | |
> | o | baz
> | /
> +---o d
> | |
> +---o c
> | |
> o | b
> |/
> o a
> EOS
$ hg log -G -T '{desc}'
o foo
|\
| | o d
| |/
| | o c
| |/
| | o bar
| |/|
| o | b
| |/
o / baz
/
o a
$ reinit
$ hg debugdrawdag <<'EOS'
> o foo
> |\
> | | o d
> | |/
> | | o c
> | |/
> | | o bar
> | |/|
> | o | b
> | |/
> o / baz
> /
> o a
> EOS
$ hg log -G -T '{desc}'
o foo
|\
| | o d
| |/
| | o c
| |/
| | o bar
| |/|
| o | b
| |/
o / baz
/
o a
Edges existed in repo are no-ops
$ reinit
$ hg debugdrawdag <<'EOS'
> B C C
> | | |
> A A B
> EOS
$ hg log -G -T '{desc}'
o C
|\
| o B
|/
o A
$ hg debugdrawdag <<'EOS'
> C D C
> | | |
> B B A
> EOS
$ hg log -G -T '{desc}'
o D
|
| o C
|/|
o | B
|/
o A
Node with more than 2 parents are disallowed
$ hg debugdrawdag <<'EOS'
> A
> /|\
> D B C
> EOS
abort: A: too many parents: C D B
[255]
Cycles are disallowed
$ hg debugdrawdag <<'EOS'
> A
> |
> A
> EOS
abort: the graph has cycles
[255]
$ hg debugdrawdag <<'EOS'
> A
> |
> B
> |
> A
> EOS
abort: the graph has cycles
[255]