import-checkers: split tests of the tool from running it on the source

We did such splits for other tools already. The 'test-check-*.t' performs the
check of the source code while the regular tests verifies the tools works.

One of the benefit is that is provides a simple file to reuse in third party
extensions.

tests/test-check-module-imports.t

@@ -3,148 +3,6 b''
   $ . "$TESTDIR/helpers-testrepo.sh"
   $ import_checker="$TESTDIR"/../contrib/import-checker.py
 
-Run the doctests from the import checker, and make sure
-it's working correctly.
-  $ TERM=dumb
-  $ export TERM
-  $ python -m doctest $import_checker
-
-Run additional tests for the import checker
-
-  $ mkdir testpackage
-  $ touch testpackage/__init__.py
-
-  $ cat > testpackage/multiple.py << EOF
-  > from __future__ import absolute_import
-  > import os, sys
-  > EOF
-
-  $ cat > testpackage/unsorted.py << EOF
-  > from __future__ import absolute_import
-  > import sys
-  > import os
-  > EOF
-
-  $ cat > testpackage/stdafterlocal.py << EOF
-  > from __future__ import absolute_import
-  > from . import unsorted
-  > import os
-  > EOF
-
-  $ cat > testpackage/requirerelative.py << EOF
-  > from __future__ import absolute_import
-  > import testpackage.unsorted
-  > EOF
-
-  $ cat > testpackage/importalias.py << EOF
-  > from __future__ import absolute_import
-  > import ui
-  > EOF
-
-  $ cat > testpackage/relativestdlib.py << EOF
-  > from __future__ import absolute_import
-  > from .. import os
-  > EOF
-
-  $ cat > testpackage/symbolimport.py << EOF
-  > from __future__ import absolute_import
-  > from .unsorted import foo
-  > EOF
-
-  $ cat > testpackage/latesymbolimport.py << EOF
-  > from __future__ import absolute_import
-  > from . import unsorted
-  > from mercurial.node import hex
-  > EOF
-
-  $ cat > testpackage/multiplegroups.py << EOF
-  > from __future__ import absolute_import
-  > from . import unsorted
-  > from . import more
-  > EOF
-
-  $ mkdir testpackage/subpackage
-  $ cat > testpackage/subpackage/levelpriority.py << EOF
-  > from __future__ import absolute_import
-  > from . import foo
-  > from .. import parent
-  > EOF
-
-  $ touch testpackage/subpackage/foo.py
-  $ cat > testpackage/subpackage/__init__.py << EOF
-  > from __future__ import absolute_import
-  > from . import levelpriority  # should not cause cycle
-  > EOF
-
-  $ cat > testpackage/subpackage/localimport.py << EOF
-  > from __future__ import absolute_import
-  > from . import foo
-  > def bar():
-  >     # should not cause "higher-level import should come first"
-  >     from .. import unsorted
-  >     # but other errors should be detected
-  >     from .. import more
-  >     import testpackage.subpackage.levelpriority
-  > EOF
-
-  $ cat > testpackage/importmodulefromsub.py << EOF
-  > from __future__ import absolute_import
-  > from .subpackage import foo  # not a "direct symbol import"
-  > EOF
-
-  $ cat > testpackage/importsymbolfromsub.py << EOF
-  > from __future__ import absolute_import
-  > from .subpackage import foo, nonmodule
-  > EOF
-
-  $ cat > testpackage/sortedentries.py << EOF
-  > from __future__ import absolute_import
-  > from . import (
-  >     foo,
-  >     bar,
-  > )
-  > EOF
-
-  $ cat > testpackage/importfromalias.py << EOF
-  > from __future__ import absolute_import
-  > from . import ui
-  > EOF
-
-  $ cat > testpackage/importfromrelative.py << EOF
-  > from __future__ import absolute_import
-  > from testpackage.unsorted import foo
-  > EOF
-
-  $ mkdir testpackage2
-  $ touch testpackage2/__init__.py
-
-  $ cat > testpackage2/latesymbolimport.py << EOF
-  > from __future__ import absolute_import
-  > from testpackage import unsorted
-  > from mercurial.node import hex
-  > EOF
-
-  $ python "$import_checker" testpackage*/*.py testpackage/subpackage/*.py
-  testpackage/importalias.py:2: ui module must be "as" aliased to uimod
-  testpackage/importfromalias.py:2: ui from testpackage must be "as" aliased to uimod
-  testpackage/importfromrelative.py:2: import should be relative: testpackage.unsorted
-  testpackage/importfromrelative.py:2: direct symbol import foo from testpackage.unsorted
-  testpackage/importsymbolfromsub.py:2: direct symbol import nonmodule from testpackage.subpackage
-  testpackage/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
-  testpackage/multiple.py:2: multiple imported names: os, sys
-  testpackage/multiplegroups.py:3: multiple "from . import" statements
-  testpackage/relativestdlib.py:2: relative import of stdlib module
-  testpackage/requirerelative.py:2: import should be relative: testpackage.unsorted
-  testpackage/sortedentries.py:2: imports from testpackage not lexically sorted: bar < foo
-  testpackage/stdafterlocal.py:3: stdlib import "os" follows local import: testpackage
-  testpackage/subpackage/levelpriority.py:3: higher-level import should come first: testpackage
-  testpackage/subpackage/localimport.py:7: multiple "from .. import" statements
-  testpackage/subpackage/localimport.py:8: import should be relative: testpackage.subpackage.levelpriority
-  testpackage/symbolimport.py:2: direct symbol import foo from testpackage.unsorted
-  testpackage/unsorted.py:3: imports not lexically sorted: os < sys
-  testpackage2/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
-  [1]
-
   $ cd "$TESTDIR"/..
 
 There are a handful of cases here that require renaming a module so it
@@ -171,7 +29,7 b' outputs, which should be fixed later.'
   > -X tests/test-verify-repo-operations.py \
   > -X tests/test-hook.t \
   > -X tests/test-import.t \
-  > -X tests/test-check-module-imports.t \
+  > -X tests/test-imports-checker.t \
   > -X tests/test-commit-interactive.t \
   > -X tests/test-contrib-check-code.t \
   > -X tests/test-extension.t \

tests/test-imports-checker.t

@@ -144,39 +144,3 b' Run additional tests for the import chec'
   testpackage/unsorted.py:3: imports not lexically sorted: os < sys
   testpackage2/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
   [1]
-
-  $ cd "$TESTDIR"/..
-
-There are a handful of cases here that require renaming a module so it
-doesn't overlap with a stdlib module name. There are also some cycles
-here that we should still endeavor to fix, and some cycles will be
-hidden by deduplication algorithm in the cycle detector, so fixing
-these may expose other cycles.
-
-Known-bad files are excluded by -X as some of them would produce unstable
-outputs, which should be fixed later.
-
-  $ hg locate 'set:**.py or grep(r"^#!.*?python")' \
-  > 'tests/**.t' \
-  > -X contrib/debugshell.py \
-  > -X contrib/python-zstandard/ \
-  > -X contrib/win32/hgwebdir_wsgi.py \
-  > -X doc/gendoc.py \
-  > -X doc/hgmanpage.py \
-  > -X i18n/posplit \
-  > -X tests/test-hgweb-auth.py \
-  > -X tests/hypothesishelpers.py \
-  > -X tests/test-ctxmanager.py \
-  > -X tests/test-lock.py \
-  > -X tests/test-verify-repo-operations.py \
-  > -X tests/test-hook.t \
-  > -X tests/test-import.t \
-  > -X tests/test-check-module-imports.t \
-  > -X tests/test-commit-interactive.t \
-  > -X tests/test-contrib-check-code.t \
-  > -X tests/test-extension.t \
-  > -X tests/test-hghave.t \
-  > -X tests/test-hgweb-no-path-info.t \
-  > -X tests/test-hgweb-no-request-uri.t \
-  > -X tests/test-hgweb-non-interactive.t \
-  > | sed 's-\\-/-g' | python "$import_checker" -