tests/test-unified-test.t

help: eliminate duplicate text for revset string patterns

There's no reason to duplicate this so many times, and it's likely an instance
will be missed if support for a new pattern is added and documented.  The
stringmatcher is mostly used by revsets, though it is also used for the 'tag'
related templates, and namespace filtering in the journal extension.  So maybe
there's a better place to document it.  `hg help patterns` seems inappropriate,
because that is all file pattern matching.

While here, indicate how to perform case insensitive regex searches.

Test that the syntax of "unified tests" is properly processed
==============================================================

Simple commands:

  $ echo foo
  foo
  $ printf 'oh no'
  oh no (no-eol)
  $ printf 'bar\nbaz\n' | cat
  bar
  baz

Multi-line command:

  $ foo() {
  >     echo bar
  > }
  $ foo
  bar

Return codes before inline python:

  $ sh -c 'exit 1'
  [1]

Doctest commands:

  >>> from __future__ import print_function
  >>> print('foo')
  foo
  $ echo interleaved
  interleaved
  >>> for c in 'xyz':
  ...     print(c)
  x
  y
  z
  >>> print()
  
  >>> foo = 'global name'
  >>> def func():
  ...     print(foo, 'should be visible in func()')
  >>> func()
  global name should be visible in func()
  >>> print('''multiline
  ... string''')
  multiline
  string

Regular expressions:

  $ echo foobarbaz
  foobar.* (re)
  $ echo barbazquux
  .*quux.* (re)

Globs:

  $ printf '* \\foobarbaz {10}\n'
  \* \\fo?bar* {10} (glob)

Literal match ending in " (re)":

  $ echo 'foo (re)'
  foo (re)

Windows: \r\n is handled like \n and can be escaped:

#if windows
  $ printf 'crlf\r\ncr\r\tcrlf\r\ncrlf\r\n'
  crlf
  cr\r (no-eol) (esc)
  \tcrlf (esc)
  crlf\r (esc)
#endif

Combining esc with other markups - and handling lines ending with \r instead of \n:

  $ printf 'foo/bar\r'
  fo?/bar\r (no-eol) (glob) (esc)
#if windows
  $ printf 'foo\\bar\r'
  foo/bar\r (no-eol) (glob) (esc)
#endif
  $ printf 'foo/bar\rfoo/bar\r'
  foo.bar\r \(no-eol\) (re) (esc)
  foo.bar\r \(no-eol\) (re)

testing hghave

  $ hghave true
  $ hghave false
  skipped: missing feature: nail clipper
  [1]
  $ hghave no-true
  skipped: system supports yak shaving
  [1]
  $ hghave no-false

Conditional sections based on hghave:

#if true
  $ echo tested
  tested
#else
  $ echo skipped
#endif

#if false
  $ echo skipped
#else
  $ echo tested
  tested
#endif

#if no-false
  $ echo tested
  tested
#else
  $ echo skipped
#endif

#if no-true
  $ echo skipped
#else
  $ echo tested
  tested
#endif

Exit code:

  $ (exit 1)
  [1]