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Differential D2608

templater: add hint to template parse errors to help locate issues
ClosedPublic

Authored by ryanmce on Mar 3 2018, 4:49 PM.

Details

Reviewers
durin42
Group Reviewers
hg-reviewers
Commits
rHG80d7fb6c2dec: templater: add hint to template parse errors to help locate issues
rHG8df20b7a39d2: templater: add hint to template parse errors to help locate issues
Summary

Previously, we would print the error name and location, but this isn't as
helpful as we can be. Let's add a hint that shows the location where we
encountered the parse error.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

ryanmce created this revision.Mar 3 2018, 4:49 PM
durin42 requested changes to this revision.Mar 3 2018, 4:55 PM
durin42 added a subscriber: durin42.

We should add a test about templates that contain newlines - it's probably Hard, so feel free to just not be helpful with newline-containing templates for now?

tests/test-command-template.t
2770

Nit: could we make this be "^ here" instead of just the caret?

This revision now requires changes to proceed.Mar 3 2018, 4:55 PM
ryanmce updated this revision to Diff 6484.Mar 3 2018, 5:11 PM
pulkit added a subscriber: pulkit.Mar 3 2018, 5:17 PM

I like similar things in rust too. I am +1 on this.

durin42 accepted this revision.Mar 3 2018, 5:42 PM
This revision is now accepted and ready to land.Mar 3 2018, 5:42 PM
Closed by commit rHG8df20b7a39d2: templater: add hint to template parse errors to help locate issues (authored by ryanmce). · Explain WhyMar 3 2018, 6:39 PM
This revision was automatically updated to reflect the committed changes.
yuja added a subscriber: yuja.Mar 3 2018, 7:21 PM
yuja added inline comments.
mercurial/templater.py
148

Perhaps this pos + 1 is the reason why the error location is sometimes wrong.
I'll send a follow up.

Revision Contents
Changeset List

PathPackages
Mmercurial/templater.py (67 lines)
Mtests/test-command-template.t (18 lines)
Mtests/test-export.t (2 lines)
Mtests/test-log.t (17 lines)

Diff 6509

mercurial/templater.py

d = program[pos] d = program[pos]
if not (d.isalnum() or d == "_"): if not (d.isalnum() or d == "_"):
break break
pos += 1 pos += 1
sym = program[s:pos] sym = program[s:pos]
yield ('symbol', sym, s) yield ('symbol', sym, s)
pos -= 1 pos -= 1
elif c == term: elif c == term:
yield ('end', None, pos + 1) yield ('end', None, pos + 1)
yujaUnsubmitted
Not Done

Perhaps this pos + 1 is the reason why the error location is sometimes wrong.
I'll send a follow up.

yuja: Perhaps this `pos + 1` is the reason why the error location is sometimes wrong. I'll send a…
return return
else: else:
raise error.ParseError(_("syntax error"), pos) raise error.ParseError(_("syntax error"), pos)
pos += 1 pos += 1
if term: if term:
raise error.ParseError(_("unterminated template expansion"), start) raise error.ParseError(_("unterminated template expansion"), start)
yield ('end', None, pos) yield ('end', None, pos)
raise error.ProgrammingError('unterminated scanning of template') raise error.ProgrammingError('unterminated scanning of template')
def _scantemplate(tmpl, start, stop, quote='', raw=False): def _scantemplate(tmpl, start, stop, quote='', raw=False):
"""Parse template string into chunks of strings and template expressions""" """Parse template string into chunks of strings and template expressions"""
sepchars = '{' + quote sepchars = '{' + quote
unescape = [parser.unescapestr, pycompat.identity][raw] unescape = [parser.unescapestr, pycompat.identity][raw]
pos = start pos = start
p = parser.parser(elements) p = parser.parser(elements)
try:
while pos < stop: while pos < stop:
n = min((tmpl.find(c, pos, stop) for c in sepchars), n = min((tmpl.find(c, pos, stop) for c in sepchars),
key=lambda n: (n < 0, n)) key=lambda n: (n < 0, n))
if n < 0: if n < 0:
yield ('string', unescape(tmpl[pos:stop]), pos) yield ('string', unescape(tmpl[pos:stop]), pos)
pos = stop pos = stop
break break
c = tmpl[n:n + 1] c = tmpl[n:n + 1]
bs = 0 # count leading backslashes bs = 0 # count leading backslashes
if not raw: if not raw:
bs = (n - pos) - len(tmpl[pos:n].rstrip('\\')) bs = (n - pos) - len(tmpl[pos:n].rstrip('\\'))
if bs % 2 == 1: if bs % 2 == 1:
# escaped (e.g. '\{', '\\\{', but not '\\{') # escaped (e.g. '\{', '\\\{', but not '\\{')
yield ('string', unescape(tmpl[pos:n - 1]) + c, pos) yield ('string', unescape(tmpl[pos:n - 1]) + c, pos)
pos = n + 1 pos = n + 1
continue continue
if n > pos: if n > pos:
yield ('string', unescape(tmpl[pos:n]), pos) yield ('string', unescape(tmpl[pos:n]), pos)
if c == quote: if c == quote:
yield ('end', None, n + 1) yield ('end', None, n + 1)
return return
parseres, pos = p.parse(tokenize(tmpl, n + 1, stop, '}')) parseres, pos = p.parse(tokenize(tmpl, n + 1, stop, '}'))
if not tmpl.endswith('}', n + 1, pos): if not tmpl.endswith('}', n + 1, pos):
raise error.ParseError(_("invalid token"), pos) raise error.ParseError(_("invalid token"), pos)
yield ('template', parseres, n) yield ('template', parseres, n)
if quote: if quote:
raise error.ParseError(_("unterminated string"), start) raise error.ParseError(_("unterminated string"), start)
except error.ParseError as inst:
if len(inst.args) > 1: # has location
loc = inst.args[1]
# TODO: Opportunity for improvement! If there is a newline in the
# template, this hint does not point to the right place, so skip.
if '\n' not in tmpl:
# We want the caret to point to the place in the template that
# failed to parse, but in a hint we get a open paren at the
# start. Therefore, we print "loc" spaces (instead of "loc - 1")
# to line up the caret with the location of the error.
inst.hint = tmpl + '\n' + ' ' * (loc) + '^ ' + _('here')
raise
yield ('end', None, pos) yield ('end', None, pos)
def _unnesttemplatelist(tree): def _unnesttemplatelist(tree):
"""Expand list of templates to node tuple """Expand list of templates to node tuple
>>> def f(tree): >>> def f(tree):
... print(pycompat.sysstr(prettyformat(_unnesttemplatelist(tree)))) ... print(pycompat.sysstr(prettyformat(_unnesttemplatelist(tree))))
>>> f((b'template', [])) >>> f((b'template', []))

tests/test-command-template.t

$ echo 'x = "f' >> t $ echo 'x = "f' >> t
$ hg log $ hg log
hg: parse error at t:3: unmatched quotes hg: parse error at t:3: unmatched quotes
[255] [255]
$ hg log -T '{date' $ hg log -T '{date'
hg: parse error at 1: unterminated template expansion hg: parse error at 1: unterminated template expansion
({date
^ here)
durin42Unsubmitted
Not Done

Nit: could we make this be "^ here" instead of just the caret?

durin42: Nit: could we make this be "^ here" instead of just the caret?
[255] [255]
$ hg log -T '{date(}' $ hg log -T '{date(}'
hg: parse error at 7: not a prefix: end hg: parse error at 7: not a prefix: end
({date(}
^ here)
[255] [255]
$ hg log -T '{date)}' $ hg log -T '{date)}'
hg: parse error at 5: invalid token hg: parse error at 5: invalid token
({date)}
^ here)
[255] [255]
$ hg log -T '{date date}' $ hg log -T '{date date}'
hg: parse error at 6: invalid token hg: parse error at 6: invalid token
({date date}
^ here)
[255] [255]
$ hg log -T '{}' $ hg log -T '{}'
hg: parse error at 2: not a prefix: end hg: parse error at 2: not a prefix: end
({}
^ here)
[255] [255]
$ hg debugtemplate -v '{()}' $ hg debugtemplate -v '{()}'
(template (template
(group (group
None)) None))
hg: parse error: missing argument hg: parse error: missing argument
[255] [255]
$ hg tip -T '{get(extras, "branch")|shortdate}\n' $ hg tip -T '{get(extras, "branch")|shortdate}\n'
abort: incompatible use of template filter 'shortdate' abort: incompatible use of template filter 'shortdate'
[255] [255]
Error in nested template: Error in nested template:
$ hg log -T '{"date' $ hg log -T '{"date'
hg: parse error at 2: unterminated string hg: parse error at 2: unterminated string
({"date
^ here)
[255] [255]
$ hg log -T '{"foo{date|?}"}' $ hg log -T '{"foo{date|?}"}'
hg: parse error at 11: syntax error hg: parse error at 11: syntax error
({"foo{date|?}"}
^ here)
[255] [255]
Thrown an error if a template function doesn't exist Thrown an error if a template function doesn't exist
$ hg tip --template '{foo()}\n' $ hg tip --template '{foo()}\n'
hg: parse error: unknown function 'foo' hg: parse error: unknown function 'foo'
[255] [255]
(template (template
(group (group
(negate (negate
(integer '4'))) (integer '4')))
(string '\n')) (string '\n'))
-4 -4
$ hg debugtemplate '{(-)}\n' $ hg debugtemplate '{(-)}\n'
hg: parse error at 3: not a prefix: ) hg: parse error at 3: not a prefix: )
({(-)}\n
^ here)
[255] [255]
$ hg debugtemplate '{(-a)}\n' $ hg debugtemplate '{(-a)}\n'
hg: parse error: negation needs an integer argument hg: parse error: negation needs an integer argument
[255] [255]
top-level integer literal is interpreted as symbol (i.e. variable name): top-level integer literal is interpreted as symbol (i.e. variable name):
$ hg debugtemplate -D 1=one -v '{1}\n' $ hg debugtemplate -D 1=one -v '{1}\n'
escaped single quotes and errors: escaped single quotes and errors:
$ hg log -r 2 -T "{if(rev, '{if(rev, \'foo\')}')}"'\n' $ hg log -r 2 -T "{if(rev, '{if(rev, \'foo\')}')}"'\n'
foo foo
$ hg log -r 2 -T "{if(rev, '{if(rev, r\'foo\')}')}"'\n' $ hg log -r 2 -T "{if(rev, '{if(rev, r\'foo\')}')}"'\n'
foo foo
$ hg log -r 2 -T '{if(rev, "{if(rev, \")}")}\n' $ hg log -r 2 -T '{if(rev, "{if(rev, \")}")}\n'
hg: parse error at 21: unterminated string hg: parse error at 21: unterminated string
({if(rev, "{if(rev, \")}")}\n
^ here)
[255] [255]
$ hg log -r 2 -T '{if(rev, \"\\"")}\n' $ hg log -r 2 -T '{if(rev, \"\\"")}\n'
hg: parse error: trailing \ in string hg: parse error: trailing \ in string
[255] [255]
$ hg log -r 2 -T '{if(rev, r\"\\"")}\n' $ hg log -r 2 -T '{if(rev, r\"\\"")}\n'
hg: parse error: trailing \ in string hg: parse error: trailing \ in string
[255] [255]

tests/test-export.t

$ hg export -o '%' tip $ hg export -o '%' tip
abort: incomplete format spec in output filename abort: incomplete format spec in output filename
[255] [255]
$ hg export -o '%{"foo"}' tip $ hg export -o '%{"foo"}' tip
abort: incomplete format spec in output filename abort: incomplete format spec in output filename
[255] [255]
$ hg export -o '%m{' tip $ hg export -o '%m{' tip
hg: parse error at 3: unterminated template expansion hg: parse error at 3: unterminated template expansion
(%m{
^ here)
[255] [255]
$ hg export -o '%\' tip $ hg export -o '%\' tip
abort: invalid format spec '%\' in output filename abort: invalid format spec '%\' in output filename
[255] [255]
$ hg export -o '\%' tip $ hg export -o '\%' tip
abort: incomplete format spec in output filename abort: incomplete format spec in output filename
[255] [255]

tests/test-log.t

\x1b[0;31mbarlog: foo\x1b[0m (esc) \x1b[0;31mbarlog: foo\x1b[0m (esc)
user: test user: test
date: Thu Jan 01 00:00:00 1970 +0000 date: Thu Jan 01 00:00:00 1970 +0000
summary: a bunch of weird directories summary: a bunch of weird directories
$ hg --config extensions.names=../names.py log -r 0 --template '{bars}\n' $ hg --config extensions.names=../names.py log -r 0 --template '{bars}\n'
foo foo
Templater parse errors:
simple error
$ hg log -r . -T '{shortest(node}'
hg: parse error at 15: unexpected token: end
({shortest(node}
^ here)
[255]
multi-line template with error
$ hg log -r . -T 'line 1
> line2
> {shortest(node}
> line4\nline5'
hg: parse error at 28: unexpected token: end
[255]
$ cd .. $ cd ..
hg log -f dir across branches hg log -f dir across branches
$ hg init acrossbranches $ hg init acrossbranches
$ cd acrossbranches $ cd acrossbranches
$ mkdir d $ mkdir d
$ echo a > d/a && hg ci -Aqm a $ echo a > d/a && hg ci -Aqm a