annotate tests/test-cat.t @ 35190:bd8875b6473c

run-tests: mechanism to report exceptions during test execution

Sometimes when running tests you introduce a ton of exceptions.
The most extreme example of this is running Mercurial with Python 3,
which currently spews thousands of exceptions when running the test
harness.

This commit adds an opt-in feature to run-tests.py to aggregate
exceptions encountered by `hg` when running tests.

When --exceptions is used, the test harness enables the
"logexceptions" extension in the test environment. This extension
wraps the Mercurial function to handle exceptions and writes
information about the exception to a random filename in a directory
defined by the test harness via an environment variable. At the
end of the test harness, these files are parsed, aggregated, and
a list of all unique Mercurial frames triggering exceptions is
printed in order of frequency.

This feature is intended to aid Python 3 development. I've only
really tested it on Python 3. There is no shortage of improvements
that could be made. e.g. we could write a separate file containing
the exception report - maybe even an HTML report. We also don't
capture which tests demonstrate the exceptions, so there's no turnkey
way to test whether a code change made an exception disappear.
Perfect is the enemy of good. I think the current patch is useful
enough to land. Whoever uses it can send patches to imprve its
usefulness.

Differential Revision: https://phab.mercurial-scm.org/D1477

  $ hg init
  $ echo 0 > a
  $ echo 0 > b
  $ hg ci -A -m m
  adding a
  adding b
  $ hg rm a
  $ hg cat a
  0
  $ hg cat --decode a # more tests in test-encode
  0
  $ echo 1 > b
  $ hg ci -m m
  $ echo 2 > b
  $ hg cat -r 0 a
  0
  $ hg cat -r 0 b
  0
  $ hg cat -r 1 a
  a: no such file in rev 7040230c159c
  [1]
  $ hg cat -r 1 b
  1

Test multiple files

  $ echo 3 > c
  $ hg ci -Am addmore c
  $ hg cat b c
  1
  3
  $ hg cat .
  1
  3
  $ hg cat . c
  1
  3

Test fileset

  $ hg cat 'set:not(b) or a'
  3
  $ hg cat 'set:c or b'
  1
  3

  $ mkdir tmp
  $ hg cat --output tmp/HH_%H c
  $ hg cat --output tmp/RR_%R c
  $ hg cat --output tmp/h_%h c
  $ hg cat --output tmp/r_%r c
  $ hg cat --output tmp/%s_s c
  $ hg cat --output tmp/%d%%_d c
  $ hg cat --output tmp/%p_p c
  $ hg log -r . --template "{rev}: {node|short}\n"
  2: 45116003780e
  $ find tmp -type f | sort
  tmp/.%_d
  tmp/HH_45116003780e3678b333fb2c99fa7d559c8457e9
  tmp/RR_2
  tmp/c_p
  tmp/c_s
  tmp/h_45116003780e
  tmp/r_2

Test template output

  $ hg --cwd tmp cat ../b ../c -T '== {path} ({abspath}) ==\n{data}'
  == ../b (b) == (glob)
  1
  == ../c (c) == (glob)
  3

  $ hg cat b c -Tjson --output -
  [
   {
    "abspath": "b",
    "data": "1\n",
    "path": "b"
   },
   {
    "abspath": "c",
    "data": "3\n",
    "path": "c"
   }
  ]

  $ hg cat b c -Tjson --output 'tmp/%p.json'
  $ cat tmp/b.json
  [
   {
    "abspath": "b",
    "data": "1\n",
    "path": "b"
   }
  ]
  $ cat tmp/c.json
  [
   {
    "abspath": "c",
    "data": "3\n",
    "path": "c"
   }
  ]

Test working directory

  $ echo b-wdir > b
  $ hg cat -r 'wdir()' b
  b-wdir

Environment variables are not visible by default

  $ PATTERN='t4' hg log -r '.' -T "{ifcontains('PATTERN', envvars, 'yes', 'no')}\n"
  no

Environment variable visibility can be explicit

  $ PATTERN='t4' hg log -r '.' -T "{envvars % '{key} -> {value}\n'}" \
  >                 --config "experimental.exportableenviron=PATTERN"
  PATTERN -> t4

Test behavior of output when directory structure does not already exist

  $ mkdir foo
  $ echo a > foo/a
  $ hg add foo/a
  $ hg commit -qm "add foo/a"
  $ hg cat --output "output/%p" foo/a
  $ cat output/foo/a
  a