view tests/test-template-basic.t @ 39764:e4e881572382

localrepo: iteratively derive local repository type

This commit implements the dynamic local repository type derivation
that was explained in the recent commit
bfeab472e3c0 "localrepo: create new function for instantiating a local
repo object."

Instead of a static localrepository class/type which must be customized
after construction, we now dynamically construct a type by building up
base classes/types to represent specific repository interfaces.

Conceptually, the end state is similar to what was happening when
various extensions would monkeypatch the __class__ of newly-constructed
repo instances. However, the approach is inverted. Instead of making
the instance then customizing it, we do the customization up front
by influencing the behavior of the type then we instantiate that
custom type.

This approach gives us much more flexibility. For example, we can
use completely separate classes for implementing different aspects
of the repository. For example, we could have one class representing
revlog-based file storage and another representing non-revlog based
file storage. When then choose which implementation to use based on
the presence of repo requirements.

A concern with this approach is that it creates a lot more types
and complexity and that complexity adds overhead. Yes, it is true that
this approach will result in more types being created. Yes, this is
more complicated than traditional "instantiate a static type." However,
I believe the alternatives to supporting alternate storage backends
are just as complicated. (Before I arrived at this solution, I had
patches storing factory functions on local repo instances for e.g.
constructing a file storage instance. We ended up having a handful
of these. And this was logically identical to assigning custom
methods. Since we were logically changing the type of the instance,
I figured it would be better to just use specialized types instead
of introducing levels of abstraction at run-time.)

On the performance front, I don't believe that having N base classes
has any significant performance overhead compared to just a single base
class. Intuition says that Python will need to iterate the base classes
to find an attribute. However, CPython caches method lookups: as long as
the __class__ or MRO isn't changing, method attribute lookup should be
constant time after first access. And non-method attributes are stored
in __dict__, of which there is only 1 per object, so the number of
base classes for __dict__ is irrelevant.

Anyway, this commit splits up the monolithic completelocalrepository
interface into sub-interfaces: 1 for file storage and 1 representing
everything else.

We've taught ``makelocalrepository()`` to call a series of factory
functions which will produce types implementing specific interfaces.
It then calls type() to create a new type from the built-up list of
base types.

This commit should be considered a start and not the end state. I
suspect we'll hit a number of problems as we start to implement
alternate storage backends:

* Passing custom arguments to __init__ and setting custom attributes
  on __dict__.
* Customizing the set of interfaces that are needed. e.g. the
  "readonly" intent could translate to not requesting an interface
  providing methods related to writing.
* More ergonomic way for extensions to insert themselves so their
  callbacks aren't unconditionally called.
* Wanting to modify vfs instances, other arguments passed to __init__.

That being said, this code is usable in its current state and I'm
convinced future commits will demonstrate the value in this approach.

Differential Revision: https://phab.mercurial-scm.org/D4642

Test template syntax and basic functionality
============================================

  $ hg init a
  $ cd a
  $ echo a > a
  $ hg add a
  $ echo line 1 > b
  $ echo line 2 >> b
  $ hg commit -l b -d '1000000 0' -u 'User Name <user@hostname>'

  $ hg add b
  $ echo other 1 > c
  $ echo other 2 >> c
  $ echo >> c
  $ echo other 3 >> c
  $ hg commit -l c -d '1100000 0' -u 'A. N. Other <other@place>'

  $ hg add c
  $ hg commit -m 'no person' -d '1200000 0' -u 'other@place'
  $ echo c >> c
  $ hg commit -m 'no user, no domain' -d '1300000 0' -u 'person'

  $ echo foo > .hg/branch
  $ hg commit -m 'new branch' -d '1400000 0' -u 'person'

  $ hg co -q 3
  $ echo other 4 >> d
  $ hg add d
  $ hg commit -m 'new head' -d '1500000 0' -u 'person'

  $ hg merge -q foo
  $ hg commit -m 'merge' -d '1500001 0' -u 'person'

Test arithmetic operators have the right precedence:

  $ hg log -l 1 -T '{date(date, "%Y") + 5 * 10} {date(date, "%Y") - 2 * 3}\n'
  2020 1964
  $ hg log -l 1 -T '{date(date, "%Y") * 5 + 10} {date(date, "%Y") * 3 - 2}\n'
  9860 5908

Test division:

  $ hg debugtemplate -r0 -v '{5 / 2} {mod(5, 2)}\n'
  (template
    (/
      (integer '5')
      (integer '2'))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (integer '5')
        (integer '2')))
    (string '\n'))
  * keywords: 
  * functions: mod
  2 1
  $ hg debugtemplate -r0 -v '{5 / -2} {mod(5, -2)}\n'
  (template
    (/
      (integer '5')
      (negate
        (integer '2')))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (integer '5')
        (negate
          (integer '2'))))
    (string '\n'))
  * keywords: 
  * functions: mod
  -3 -1
  $ hg debugtemplate -r0 -v '{-5 / 2} {mod(-5, 2)}\n'
  (template
    (/
      (negate
        (integer '5'))
      (integer '2'))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (negate
          (integer '5'))
        (integer '2')))
    (string '\n'))
  * keywords: 
  * functions: mod
  -3 1
  $ hg debugtemplate -r0 -v '{-5 / -2} {mod(-5, -2)}\n'
  (template
    (/
      (negate
        (integer '5'))
      (negate
        (integer '2')))
    (string ' ')
    (func
      (symbol 'mod')
      (list
        (negate
          (integer '5'))
        (negate
          (integer '2'))))
    (string '\n'))
  * keywords: 
  * functions: mod
  2 -1

Filters bind closer than arithmetic:

  $ hg debugtemplate -r0 -v '{revset(".")|count - 1}\n'
  (template
    (-
      (|
        (func
          (symbol 'revset')
          (string '.'))
        (symbol 'count'))
      (integer '1'))
    (string '\n'))
  * keywords: 
  * functions: count, revset
  0

But negate binds closer still:

  $ hg debugtemplate -r0 -v '{1-3|stringify}\n'
  (template
    (-
      (integer '1')
      (|
        (integer '3')
        (symbol 'stringify')))
    (string '\n'))
  * keywords: 
  * functions: stringify
  hg: parse error: arithmetic only defined on integers
  [255]
  $ hg debugtemplate -r0 -v '{-3|stringify}\n'
  (template
    (|
      (negate
        (integer '3'))
      (symbol 'stringify'))
    (string '\n'))
  * keywords: 
  * functions: stringify
  -3

Filters bind as close as map operator:

  $ hg debugtemplate -r0 -v '{desc|splitlines % "{line}\n"}'
  (template
    (%
      (|
        (symbol 'desc')
        (symbol 'splitlines'))
      (template
        (symbol 'line')
        (string '\n'))))
  * keywords: desc, line
  * functions: splitlines
  line 1
  line 2

Keyword arguments:

  $ hg debugtemplate -r0 -v '{foo=bar|baz}'
  (template
    (keyvalue
      (symbol 'foo')
      (|
        (symbol 'bar')
        (symbol 'baz'))))
  * keywords: bar, foo
  * functions: baz
  hg: parse error: can't use a key-value pair in this context
  [255]

  $ hg debugtemplate '{pad("foo", width=10, left=true)}\n'
         foo

Call function which takes named arguments by filter syntax:

  $ hg debugtemplate '{" "|separate}'
  $ hg debugtemplate '{("not", "an", "argument", "list")|separate}'
  hg: parse error: unknown method 'list'
  [255]

Second branch starting at nullrev:

  $ hg update null
  0 files updated, 0 files merged, 4 files removed, 0 files unresolved
  $ echo second > second
  $ hg add second
  $ hg commit -m second -d '1000000 0' -u 'User Name <user@hostname>'
  created new head

  $ echo third > third
  $ hg add third
  $ hg mv second fourth
  $ hg commit -m third -d "2020-01-01 10:01"

  $ hg log --template '{join(file_copies, ",\n")}\n' -r .
  fourth (second)
  $ hg log -T '{file_copies % "{source} -> {name}\n"}' -r .
  second -> fourth
  $ hg log -T '{rev} {ifcontains("fourth", file_copies, "t", "f")}\n' -r .:7
  8 t
  7 f

Internal resources shouldn't be exposed (issue5699):

  $ hg log -r. -T '{cache}{ctx}{repo}{revcache}{templ}{ui}'

Never crash on internal resource not available:

  $ hg --cwd .. debugtemplate '{"c0bebeef"|shortest}\n'
  abort: template resource not available: repo
  [255]

  $ hg config -T '{author}'

Quoting for ui.logtemplate

  $ hg tip --config "ui.logtemplate={rev}\n"
  8
  $ hg tip --config "ui.logtemplate='{rev}\n'"
  8
  $ hg tip --config 'ui.logtemplate="{rev}\n"'
  8
  $ hg tip --config 'ui.logtemplate=n{rev}\n'
  n8

Check that recursive reference does not fall into RuntimeError (issue4758):

 common mistake:

  $ cat << EOF > issue4758
  > changeset = '{changeset}\n'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'changeset' in template
  [255]

 circular reference:

  $ cat << EOF > issue4758
  > changeset = '{foo}'
  > foo = '{changeset}'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'foo' in template
  [255]

 buildmap() -> gettemplate(), where no thunk was made:

  $ cat << EOF > issue4758
  > changeset = '{files % changeset}\n'
  > EOF
  $ hg log --style ./issue4758
  abort: recursive reference 'changeset' in template
  [255]

 not a recursion if a keyword of the same name exists:

  $ cat << EOF > issue4758
  > changeset = '{tags % rev}'
  > rev = '{rev} {tag}\n'
  > EOF
  $ hg log --style ./issue4758 -r tip
  8 tip

Set up phase:

  $ hg phase -r 5 --public
  $ hg phase -r 7 --secret --force

Add a dummy commit to make up for the instability of the above:

  $ echo a > a
  $ hg add a
  $ hg ci -m future

Add a commit that does all possible modifications at once

  $ echo modify >> third
  $ touch b
  $ hg add b
  $ hg mv fourth fifth
  $ hg rm a
  $ hg ci -m "Modify, add, remove, rename"

Error on syntax:

  $ cat <<EOF > t
  > changeset = '{c}'
  > c = q
  > x = "f
  > EOF
  $ echo '[ui]' > .hg/hgrc
  $ echo 'style = t' >> .hg/hgrc
  $ hg log
  hg: parse error at t:3: unmatched quotes
  [255]

  $ hg log -T '{date'
  hg: parse error at 1: unterminated template expansion
  ({date
    ^ here)
  [255]
  $ hg log -T '{date(}'
  hg: parse error at 6: not a prefix: end
  ({date(}
         ^ here)
  [255]
  $ hg log -T '{date)}'
  hg: parse error at 5: invalid token
  ({date)}
        ^ here)
  [255]
  $ hg log -T '{date date}'
  hg: parse error at 6: invalid token
  ({date date}
         ^ here)
  [255]

  $ hg log -T '{}'
  hg: parse error at 1: not a prefix: end
  ({}
    ^ here)
  [255]
  $ hg debugtemplate -v '{()}'
  (template
    (group
      None))
  * keywords: 
  * functions: 
  hg: parse error: missing argument
  [255]

Behind the scenes, this would throw TypeError without intype=bytes

  $ hg log -l 3 --template '{date|obfuscate}\n'
  &#48;&#46;&#48;&#48;
  &#48;&#46;&#48;&#48;
  &#49;&#53;&#55;&#55;&#56;&#55;&#50;&#56;&#54;&#48;&#46;&#48;&#48;

Behind the scenes, this will throw a ValueError

  $ hg log -l 3 --template 'line: {desc|shortdate}\n'
  hg: parse error: invalid date: 'Modify, add, remove, rename'
  (template filter 'shortdate' is not compatible with keyword 'desc')
  [255]

Behind the scenes, this would throw AttributeError without intype=bytes

  $ hg log -l 3 --template 'line: {date|escape}\n'
  line: 0.00
  line: 0.00
  line: 1577872860.00

  $ hg log -l 3 --template 'line: {extras|localdate}\n'
  hg: parse error: localdate expects a date information
  [255]

Behind the scenes, this will throw ValueError

  $ hg tip --template '{author|email|date}\n'
  hg: parse error: date expects a date information
  [255]

  $ hg tip -T '{author|email|shortdate}\n'
  hg: parse error: invalid date: 'test'
  (template filter 'shortdate' is not compatible with keyword 'author')
  [255]

  $ hg tip -T '{get(extras, "branch")|shortdate}\n'
  hg: parse error: invalid date: 'default'
  (incompatible use of template filter 'shortdate')
  [255]

Error in nested template:

  $ hg log -T '{"date'
  hg: parse error at 2: unterminated string
  ({"date
     ^ here)
  [255]

  $ hg log -T '{"foo{date|?}"}'
  hg: parse error at 11: syntax error
  ({"foo{date|?}"}
              ^ here)
  [255]

Thrown an error if a template function doesn't exist

  $ hg tip --template '{foo()}\n'
  hg: parse error: unknown function 'foo'
  [255]

  $ cd ..

Set up latesttag repository:

  $ hg init latesttag
  $ cd latesttag

  $ echo a > file
  $ hg ci -Am a -d '0 0'
  adding file

  $ echo b >> file
  $ hg ci -m b -d '1 0'

  $ echo c >> head1
  $ hg ci -Am h1c -d '2 0'
  adding head1

  $ hg update -q 1
  $ echo d >> head2
  $ hg ci -Am h2d -d '3 0'
  adding head2
  created new head

  $ echo e >> head2
  $ hg ci -m h2e -d '4 0'

  $ hg merge -q
  $ hg ci -m merge -d '5 -3600'

  $ hg tag -r 1 -m t1 -d '6 0' t1
  $ hg tag -r 2 -m t2 -d '7 0' t2
  $ hg tag -r 3 -m t3 -d '8 0' t3
  $ hg tag -r 4 -m t4 -d '4 0' t4 # older than t2, but should not matter
  $ hg tag -r 5 -m t5 -d '9 0' t5
  $ hg tag -r 3 -m at3 -d '10 0' at3

  $ cd ..

Test new-style inline templating:

  $ hg log -R latesttag -r tip --template 'modified files: {file_mods % " {file}\n"}\n'
  modified files:  .hgtags
  

  $ hg log -R latesttag -r tip -T '{rev % "a"}\n'
  hg: parse error: 11 is not iterable of mappings
  (keyword 'rev' does not support map operation)
  [255]
  $ hg log -R latesttag -r tip -T '{get(extras, "unknown") % "a"}\n'
  hg: parse error: None is not iterable of mappings
  [255]
  $ hg log -R latesttag -r tip -T '{extras % "{key}\n" % "{key}\n"}'
  hg: parse error: list of strings is not mappable
  [255]

Test new-style inline templating of non-list/dict type:

  $ hg log -R latesttag -r tip -T '{manifest}\n'
  11:2bc6e9006ce2
  $ hg log -R latesttag -r tip -T 'string length: {manifest|count}\n'
  string length: 15
  $ hg log -R latesttag -r tip -T '{manifest % "{rev}:{node}"}\n'
  11:2bc6e9006ce29882383a22d39fd1f4e66dd3e2fc

  $ hg log -R latesttag -r tip -T '{get(extras, "branch") % "{key}: {value}\n"}'
  branch: default
  $ hg log -R latesttag -r tip -T '{get(extras, "unknown") % "{key}\n"}'
  hg: parse error: None is not iterable of mappings
  [255]
  $ hg log -R latesttag -r tip -T '{min(extras) % "{key}: {value}\n"}'
  branch: default
  $ hg log -R latesttag -l1 -T '{min(revset("0:9")) % "{rev}:{node|short}\n"}'
  0:ce3cec86e6c2
  $ hg log -R latesttag -l1 -T '{max(revset("0:9")) % "{rev}:{node|short}\n"}'
  9:fbc7cd862e9c

Test dot operator precedence:

  $ hg debugtemplate -R latesttag -r0 -v '{manifest.node|short}\n'
  (template
    (|
      (.
        (symbol 'manifest')
        (symbol 'node'))
      (symbol 'short'))
    (string '\n'))
  * keywords: manifest, node, rev
  * functions: formatnode, short
  89f4071fec70

 (the following examples are invalid, but seem natural in parsing POV)

  $ hg debugtemplate -R latesttag -r0 -v '{foo|bar.baz}\n' 2> /dev/null
  (template
    (|
      (symbol 'foo')
      (.
        (symbol 'bar')
        (symbol 'baz')))
    (string '\n'))
  [255]
  $ hg debugtemplate -R latesttag -r0 -v '{foo.bar()}\n' 2> /dev/null
  (template
    (.
      (symbol 'foo')
      (func
        (symbol 'bar')
        None))
    (string '\n'))
  * keywords: foo
  * functions: bar
  [255]

Test evaluation of dot operator:

  $ hg log -R latesttag -l1 -T '{min(revset("0:9")).node}\n'
  ce3cec86e6c26bd9bdfc590a6b92abc9680f1796
  $ hg log -R latesttag -r0 -T '{extras.branch}\n'
  default
  $ hg log -R latesttag -r0 -T '{date.unixtime} {localdate(date, "+0200").tzoffset}\n'
  0 -7200

  $ hg log -R latesttag -l1 -T '{author.invalid}\n'
  hg: parse error: 'test' is not a dictionary
  (keyword 'author' does not support member operation)
  [255]
  $ hg log -R latesttag -l1 -T '{min("abc").invalid}\n'
  hg: parse error: 'a' is not a dictionary
  [255]

Test integer literal:

  $ hg debugtemplate -v '{(0)}\n'
  (template
    (group
      (integer '0'))
    (string '\n'))
  * keywords: 
  * functions: 
  0
  $ hg debugtemplate -v '{(123)}\n'
  (template
    (group
      (integer '123'))
    (string '\n'))
  * keywords: 
  * functions: 
  123
  $ hg debugtemplate -v '{(-4)}\n'
  (template
    (group
      (negate
        (integer '4')))
    (string '\n'))
  * keywords: 
  * functions: 
  -4
  $ hg debugtemplate '{(-)}\n'
  hg: parse error at 3: not a prefix: )
  ({(-)}\n
      ^ here)
  [255]
  $ hg debugtemplate '{(-a)}\n'
  hg: parse error: negation needs an integer argument
  [255]

top-level integer literal is interpreted as symbol (i.e. variable name):

  $ hg debugtemplate -D 1=one -v '{1}\n'
  (template
    (integer '1')
    (string '\n'))
  * keywords: 
  * functions: 
  one
  $ hg debugtemplate -D 1=one -v '{if("t", "{1}")}\n'
  (template
    (func
      (symbol 'if')
      (list
        (string 't')
        (template
          (integer '1'))))
    (string '\n'))
  * keywords: 
  * functions: if
  one
  $ hg debugtemplate -D 1=one -v '{1|stringify}\n'
  (template
    (|
      (integer '1')
      (symbol 'stringify'))
    (string '\n'))
  * keywords: 
  * functions: stringify
  one

unless explicit symbol is expected:

  $ hg log -Ra -r0 -T '{desc|1}\n'
  hg: parse error: expected a symbol, got 'integer'
  [255]
  $ hg log -Ra -r0 -T '{1()}\n'
  hg: parse error: expected a symbol, got 'integer'
  [255]

Test string literal:

  $ hg debugtemplate -Ra -r0 -v '{"string with no template fragment"}\n'
  (template
    (string 'string with no template fragment')
    (string '\n'))
  * keywords: 
  * functions: 
  string with no template fragment
  $ hg debugtemplate -Ra -r0 -v '{"template: {rev}"}\n'
  (template
    (template
      (string 'template: ')
      (symbol 'rev'))
    (string '\n'))
  * keywords: rev
  * functions: 
  template: 0
  $ hg debugtemplate -Ra -r0 -v '{r"rawstring: {rev}"}\n'
  (template
    (string 'rawstring: {rev}')
    (string '\n'))
  * keywords: 
  * functions: 
  rawstring: {rev}
  $ hg debugtemplate -Ra -r0 -v '{files % r"rawstring: {file}"}\n'
  (template
    (%
      (symbol 'files')
      (string 'rawstring: {file}'))
    (string '\n'))
  * keywords: files
  * functions: 
  rawstring: {file}

Test string escaping:

  $ hg log -R latesttag -r 0 --template '>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ hg log -R latesttag -r 0 \
  > --config ui.logtemplate='>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ hg log -R latesttag -r 0 -T esc \
  > --config templates.esc='>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  >
  <>\n<[>
  <>\n<]>
  <>\n<

  $ cat <<'EOF' > esctmpl
  > changeset = '>\n<>\\n<{if(rev, "[>\n<>\\n<]")}>\n<>\\n<\n'
  > EOF
  $ hg log -R latesttag -r 0 --style ./esctmpl
  >
  <>\n<[>
  <>\n<]>
  <>\n<

Test string escaping of quotes:

  $ hg log -Ra -r0 -T '{"\""}\n'
  "
  $ hg log -Ra -r0 -T '{"\\\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\\\""}\n'
  \\\"


  $ hg log -Ra -r0 -T '{"\""}\n'
  "
  $ hg log -Ra -r0 -T '{"\\\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\""}\n'
  \"
  $ hg log -Ra -r0 -T '{r"\\\""}\n'
  \\\"

Test exception in quoted template. single backslash before quotation mark is
stripped before parsing:

  $ cat <<'EOF' > escquotetmpl
  > changeset = "\" \\" \\\" \\\\" {files % \"{file}\"}\n"
  > EOF
  $ cd latesttag
  $ hg log -r 2 --style ../escquotetmpl
  " \" \" \\" head1

  $ hg log -r 2 -T esc --config templates.esc='"{\"valid\"}\n"'
  valid
  $ hg log -r 2 -T esc --config templates.esc="'"'{\'"'"'valid\'"'"'}\n'"'"
  valid

Test compatibility with 2.9.2-3.4 of escaped quoted strings in nested
_evalifliteral() templates (issue4733):

  $ hg log -r 2 -T '{if(rev, "\"{rev}")}\n'
  "2
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"\\\"{rev}\")}")}\n'
  "2
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, \\\"\\\\\\\"{rev}\\\")}\")}")}\n'
  "2

  $ hg log -r 2 -T '{if(rev, "\\\"")}\n'
  \"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"\\\\\\\"\")}")}\n'
  \"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, \\\"\\\\\\\\\\\\\\\"\\\")}\")}")}\n'
  \"

  $ hg log -r 2 -T '{if(rev, r"\\\"")}\n'
  \\\"
  $ hg log -r 2 -T '{if(rev, "{if(rev, r\"\\\\\\\"\")}")}\n'
  \\\"
  $ hg log -r 2 -T '{if(rev, "{if(rev, \"{if(rev, r\\\"\\\\\\\\\\\\\\\"\\\")}\")}")}\n'
  \\\"

escaped single quotes and errors:

  $ hg log -r 2 -T "{if(rev, '{if(rev, \'foo\')}')}"'\n'
  foo
  $ hg log -r 2 -T "{if(rev, '{if(rev, r\'foo\')}')}"'\n'
  foo
  $ hg log -r 2 -T '{if(rev, "{if(rev, \")}")}\n'
  hg: parse error at 21: unterminated string
  ({if(rev, "{if(rev, \")}")}\n
                        ^ here)
  [255]
  $ hg log -r 2 -T '{if(rev, \"\\"")}\n'
  hg: parse error: trailing \ in string
  [255]
  $ hg log -r 2 -T '{if(rev, r\"\\"")}\n'
  hg: parse error: trailing \ in string
  [255]

  $ cd ..

Test leading backslashes:

  $ cd latesttag
  $ hg log -r 2 -T '\{rev} {files % "\{file}"}\n'
  {rev} {file}
  $ hg log -r 2 -T '\\{rev} {files % "\\{file}"}\n'
  \2 \head1
  $ hg log -r 2 -T '\\\{rev} {files % "\\\{file}"}\n'
  \{rev} \{file}
  $ cd ..

Test leading backslashes in "if" expression (issue4714):

  $ cd latesttag
  $ hg log -r 2 -T '{if("1", "\{rev}")} {if("1", r"\{rev}")}\n'
  {rev} \{rev}
  $ hg log -r 2 -T '{if("1", "\\{rev}")} {if("1", r"\\{rev}")}\n'
  \2 \\{rev}
  $ hg log -r 2 -T '{if("1", "\\\{rev}")} {if("1", r"\\\{rev}")}\n'
  \{rev} \\\{rev}
  $ cd ..

"string-escape"-ed "\x5c\x786e" becomes r"\x6e" (once) or r"n" (twice)

  $ hg log -R a -r 0 --template '{if("1", "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 0 --template '{if("1", r"\x5c\x786e", "NG")}\n'
  \x5c\x786e
  $ hg log -R a -r 0 --template '{if("", "NG", "\x5c\x786e")}\n'
  \x6e
  $ hg log -R a -r 0 --template '{if("", "NG", r"\x5c\x786e")}\n'
  \x5c\x786e

  $ hg log -R a -r 2 --template '{ifeq("no perso\x6e", desc, "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 2 --template '{ifeq(r"no perso\x6e", desc, "NG", r"\x5c\x786e")}\n'
  \x5c\x786e
  $ hg log -R a -r 2 --template '{ifeq(desc, "no perso\x6e", "\x5c\x786e", "NG")}\n'
  \x6e
  $ hg log -R a -r 2 --template '{ifeq(desc, r"no perso\x6e", "NG", r"\x5c\x786e")}\n'
  \x5c\x786e

  $ hg log -R a -r 8 --template '{join(files, "\n")}\n'
  fourth
  second
  third
  $ hg log -R a -r 8 --template '{join(files, r"\n")}\n'
  fourth\nsecond\nthird

  $ hg log -R a -r 2 --template '{rstdoc("1st\n\n2nd", "htm\x6c")}'
  <p>
  1st
  </p>
  <p>
  2nd
  </p>
  $ hg log -R a -r 2 --template '{rstdoc(r"1st\n\n2nd", "html")}'
  <p>
  1st\n\n2nd
  </p>
  $ hg log -R a -r 2 --template '{rstdoc("1st\n\n2nd", r"htm\x6c")}'
  1st
  
  2nd

  $ hg log -R a -r 2 --template '{strip(desc, "\x6e")}\n'
  o perso
  $ hg log -R a -r 2 --template '{strip(desc, r"\x6e")}\n'
  no person
  $ hg log -R a -r 2 --template '{strip("no perso\x6e", "\x6e")}\n'
  o perso
  $ hg log -R a -r 2 --template '{strip(r"no perso\x6e", r"\x6e")}\n'
  no perso

  $ hg log -R a -r 2 --template '{sub("\\x6e", "\x2d", desc)}\n'
  -o perso-
  $ hg log -R a -r 2 --template '{sub(r"\\x6e", "-", desc)}\n'
  no person
  $ hg log -R a -r 2 --template '{sub("n", r"\\x2d", desc)}\n'
  \x2do perso\x2d
  $ hg log -R a -r 2 --template '{sub("n", "\x2d", "no perso\x6e")}\n'
  -o perso-
  $ hg log -R a -r 2 --template '{sub("n", r"\\x2d", r"no perso\x6e")}\n'
  \x2do perso\x6e

  $ hg log -R a -r 8 --template '{files % "{file}\n"}'
  fourth
  second
  third

Test string escaping in nested expression:

  $ hg log -R a -r 8 --template '{ifeq(r"\x6e", if("1", "\x5c\x786e"), join(files, "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird
  $ hg log -R a -r 8 --template '{ifeq(if("1", r"\x6e"), "\x5c\x786e", join(files, "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird

  $ hg log -R a -r 8 --template '{join(files, ifeq(branch, "default", "\x5c\x786e"))}\n'
  fourth\x6esecond\x6ethird
  $ hg log -R a -r 8 --template '{join(files, ifeq(branch, "default", r"\x5c\x786e"))}\n'
  fourth\x5c\x786esecond\x5c\x786ethird

  $ hg log -R a -r 3:4 --template '{rev}:{sub(if("1", "\x6e"), ifeq(branch, "foo", r"\x5c\x786e", "\x5c\x786e"), desc)}\n'
  3:\x6eo user, \x6eo domai\x6e
  4:\x5c\x786eew bra\x5c\x786ech

Test quotes in nested expression are evaluated just like a $(command)
substitution in POSIX shells:

  $ hg log -R a -r 8 -T '{"{"{rev}:{node|short}"}"}\n'
  8:95c24699272e
  $ hg log -R a -r 8 -T '{"{"\{{rev}} \"{node|short}\""}"}\n'
  {8} "95c24699272e"

Test recursive evaluation:

  $ hg init r
  $ cd r
  $ echo a > a
  $ hg ci -Am '{rev}'
  adding a
  $ hg log -r 0 --template '{if(rev, desc)}\n'
  {rev}
  $ hg log -r 0 --template '{if(rev, "{author} {rev}")}\n'
  test 0

  $ hg branch -q 'text.{rev}'
  $ echo aa >> aa
  $ hg ci -u '{node|short}' -m 'desc to be wrapped desc to be wrapped'

  $ hg log -l1 --template '{fill(desc, "20", author, branch)}'
  {node|short}desc to
  text.{rev}be wrapped
  text.{rev}desc to be
  text.{rev}wrapped (no-eol)
  $ hg log -l1 --template '{fill(desc, "20", "{node|short}:", "text.{rev}:")}'
  bcc7ff960b8e:desc to
  text.1:be wrapped
  text.1:desc to be
  text.1:wrapped (no-eol)
  $ hg log -l1 -T '{fill(desc, date, "", "")}\n'
  hg: parse error: fill expects an integer width
  [255]

  $ hg log -l 1 --template '{sub(r"[0-9]", "-", author)}'
  {node|short} (no-eol)
  $ hg log -l 1 --template '{sub(r"[0-9]", "-", "{node|short}")}'
  bcc-ff---b-e (no-eol)

  $ cat >> .hg/hgrc <<EOF
  > [extensions]
  > color=
  > [color]
  > mode=ansi
  > text.{rev} = red
  > text.1 = green
  > EOF
  $ hg log --color=always -l 1 --template '{label(branch, "text\n")}'
  \x1b[0;31mtext\x1b[0m (esc)
  $ hg log --color=always -l 1 --template '{label("text.{rev}", "text\n")}'
  \x1b[0;32mtext\x1b[0m (esc)

  $ cd ..

Test bad template with better error message

  $ hg log -Gv -R a --template '{desc|user()}'
  hg: parse error: expected a symbol, got 'func'
  [255]

Test broken string escapes:

  $ hg log -T "bogus\\" -R a
  hg: parse error: trailing \ in string
  [255]
  $ hg log -T "\\xy" -R a
  hg: parse error: invalid \x escape* (glob)
  [255]

Templater supports aliases of symbol and func() styles:

  $ hg clone -q a aliases
  $ cd aliases
  $ cat <<EOF >> .hg/hgrc
  > [templatealias]
  > r = rev
  > rn = "{r}:{node|short}"
  > status(c, files) = files % "{c} {file}\n"
  > utcdate(d) = localdate(d, "UTC")
  > EOF

  $ hg debugtemplate -vr0 '{rn} {utcdate(date)|isodate}\n'
  (template
    (symbol 'rn')
    (string ' ')
    (|
      (func
        (symbol 'utcdate')
        (symbol 'date'))
      (symbol 'isodate'))
    (string '\n'))
  * expanded:
  (template
    (template
      (symbol 'rev')
      (string ':')
      (|
        (symbol 'node')
        (symbol 'short')))
    (string ' ')
    (|
      (func
        (symbol 'localdate')
        (list
          (symbol 'date')
          (string 'UTC')))
      (symbol 'isodate'))
    (string '\n'))
  * keywords: date, node, rev
  * functions: isodate, localdate, short
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ hg debugtemplate -vr0 '{status("A", file_adds)}'
  (template
    (func
      (symbol 'status')
      (list
        (string 'A')
        (symbol 'file_adds'))))
  * expanded:
  (template
    (%
      (symbol 'file_adds')
      (template
        (string 'A')
        (string ' ')
        (symbol 'file')
        (string '\n'))))
  * keywords: file, file_adds
  * functions: 
  A a

A unary function alias can be called as a filter:

  $ hg debugtemplate -vr0 '{date|utcdate|isodate}\n'
  (template
    (|
      (|
        (symbol 'date')
        (symbol 'utcdate'))
      (symbol 'isodate'))
    (string '\n'))
  * expanded:
  (template
    (|
      (func
        (symbol 'localdate')
        (list
          (symbol 'date')
          (string 'UTC')))
      (symbol 'isodate'))
    (string '\n'))
  * keywords: date
  * functions: isodate, localdate
  1970-01-12 13:46 +0000

Aliases should be applied only to command arguments and templates in hgrc.
Otherwise, our stock styles and web templates could be corrupted:

  $ hg log -r0 -T '{rn} {utcdate(date)|isodate}\n'
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ hg log -r0 --config ui.logtemplate='"{rn} {utcdate(date)|isodate}\n"'
  0:1e4e1b8f71e0 1970-01-12 13:46 +0000

  $ cat <<EOF > tmpl
  > changeset = 'nothing expanded:{rn}\n'
  > EOF
  $ hg log -r0 --style ./tmpl
  nothing expanded:

Aliases in formatter:

  $ hg branches -T '{pad(branch, 7)} {rn}\n'
  default 6:d41e714fe50d
  foo     4:bbe44766e73d

Aliases should honor HGPLAIN:

  $ HGPLAIN= hg log -r0 -T 'nothing expanded:{rn}\n'
  nothing expanded:
  $ HGPLAINEXCEPT=templatealias hg log -r0 -T '{rn}\n'
  0:1e4e1b8f71e0

Unparsable alias:

  $ hg debugtemplate --config templatealias.bad='x(' -v '{bad}'
  (template
    (symbol 'bad'))
  abort: bad definition of template alias "bad": at 2: not a prefix: end
  [255]
  $ hg log --config templatealias.bad='x(' -T '{bad}'
  abort: bad definition of template alias "bad": at 2: not a prefix: end
  [255]

  $ cd ..

Test that template function in extension is registered as expected

  $ cd a

  $ cat <<EOF > $TESTTMP/customfunc.py
  > from mercurial import registrar
  > 
  > templatefunc = registrar.templatefunc()
  > 
  > @templatefunc(b'custom()')
  > def custom(context, mapping, args):
  >     return b'custom'
  > EOF
  $ cat <<EOF > .hg/hgrc
  > [extensions]
  > customfunc = $TESTTMP/customfunc.py
  > EOF

  $ hg log -r . -T "{custom()}\n" --config customfunc.enabled=true
  custom

  $ cd ..