Support empy4 together with empy3

.github/workflows/ci.yaml

@@ -12,6 +12,28 @@ jobs:
     uses: ros-infrastructure/ci/.github/workflows/pytest.yaml@main
     with:
       matrix-filter: del(.matrix.os[] | select(contains("windows")))
+
+  # Dedicated job for testing with empy < 4
+  pytest-empy-legacy:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        python-version: ['3.11', '3.12', '3.13']
+    name: Test empy < 4 compatibility (Python ${{ matrix.python-version }})
+    steps:
+      - uses: actions/checkout@v4
+      - name: Set up Python ${{ matrix.python-version }}
+        uses: actions/setup-python@v4
+        with:
+          python-version: ${{ matrix.python-version }}
+      - name: Install dependencies with empy < 4
+        run: |
+          python -m pip install --upgrade pip
+          pip install 'empy<4'
+          pip install -e .[test]
+      - name: Run tests
+        run: |
+          python -m pytest test/ -v
   yamllint:
     runs-on: ubuntu-latest
     steps:

bloom/generators/debian/generator.py

@@ -78,6 +78,8 @@
 from bloom.logging import is_debug
 from bloom.logging import warning
 
+from bloom.util import expand_template_em
+
 from bloom.commands.git.patch.common import get_patch_config
 from bloom.commands.git.patch.common import set_patch_config
 
@@ -102,23 +104,6 @@
     debug(traceback.format_exc())
     error("rosdistro was not detected, please install it.", exit=True)
 
-try:
-    import em
-except ImportError:
-    debug(traceback.format_exc())
-    error("empy was not detected, please install it.", exit=True)
-
-# Fix unicode bug in empy
-# This should be removed once upstream empy is fixed
-# See: https://github.com/ros-infrastructure/bloom/issues/196
-try:
-    em.str = unicode
-    em.Stream.write_old = em.Stream.write
-    em.Stream.write = lambda self, data: em.Stream.write_old(self, data.encode('utf8'))
-except NameError:
-    pass
-# End fix
-
 # Drop the first log prefix for this command
 enable_drop_first_log_prefix(True)
 
@@ -151,10 +136,7 @@ def __place_template_folder(group, src, dst, gbp=False):
                 debug("Not overwriting existing file '{0}'".format(template_dst))
             else:
                 with io.open(template_dst, 'w', encoding='utf-8') as f:
-                    if not isinstance(template, str):
-                        template = template.decode('utf-8')
-                    # Python 2 API needs a `unicode` not a utf-8 string.
-                    elif sys.version_info.major == 2:
+                    if isinstance(template, bytes):
                         template = template.decode('utf-8')
                     f.write(template)
                 shutil.copystat(template_abs_path, template_dst)
@@ -483,17 +465,11 @@ def generate_substitutions_from_package(
     data['Licenses'] = licenses
 
     def convertToUnicode(obj):
-        if sys.version_info.major == 2:
-            if isinstance(obj, str):
-                return unicode(obj.decode('utf8'))
-            elif isinstance(obj, unicode):
-                return obj
-        else:
-            if isinstance(obj, bytes):
-                return str(obj.decode('utf8'))
-            elif isinstance(obj, str):
-                return obj
-        if isinstance(obj, list):
+        if isinstance(obj, bytes):
+            return str(obj.decode('utf8'))
+        elif isinstance(obj, str):
+            return obj
+        elif isinstance(obj, list):
             for i, val in enumerate(obj):
                 obj[i] = convertToUnicode(val)
             return obj
@@ -534,16 +510,14 @@ def __process_template_folder(path, subs):
         info("Expanding '{0}' -> '{1}'".format(
             os.path.relpath(item),
             os.path.relpath(template_path)))
-        result = em.expand(template, **subs)
+        result = expand_template_em(template, subs)
         # Don't write an empty file
         if len(result) == 0 and \
            os.path.basename(template_path) in ['copyright']:
             processed_items.append(item)
             continue
         # Write the result
         with io.open(template_path, 'w', encoding='utf-8') as f:
-            if sys.version_info.major == 2:
-                result = result.decode('utf-8')
             f.write(result)
         # Copy the permissions
         shutil.copymode(item, template_path)

bloom/generators/rpm/generator.py

@@ -81,6 +81,7 @@
 
 from bloom.util import code
 from bloom.util import execute_command
+from bloom.util import expand_template_em
 from bloom.util import maybe_continue
 
 try:
@@ -89,12 +90,6 @@
     debug(traceback.format_exc())
     error("rosdistro was not detected, please install it.", exit=True)
 
-try:
-    import em
-except ImportError:
-    debug(traceback.format_exc())
-    error("empy was not detected, please install it.", exit=True)
-
 # Drop the first log prefix for this command
 enable_drop_first_log_prefix(True)
 
@@ -325,17 +320,11 @@ def generate_substitutions_from_package(
     summarize_dependency_mapping(data, depends, build_depends, resolved_deps)
 
     def convertToUnicode(obj):
-        if sys.version_info.major == 2:
-            if isinstance(obj, str):
-                return unicode(obj.decode('utf8'))
-            elif isinstance(obj, unicode):
-                return obj
-        else:
-            if isinstance(obj, bytes):
-                return str(obj.decode('utf8'))
-            elif isinstance(obj, str):
-                return obj
-        if isinstance(obj, list):
+        if isinstance(obj, bytes):
+            return str(obj.decode('utf8'))
+        elif isinstance(obj, str):
+            return obj
+        elif isinstance(obj, list):
             for i, val in enumerate(obj):
                 obj[i] = convertToUnicode(val)
             return obj
@@ -378,11 +367,9 @@ def __process_template_folder(path, subs):
         info("Expanding '{0}' -> '{1}'".format(
             os.path.relpath(item),
             os.path.relpath(template_path)))
-        result = em.expand(template, **subs)
+        result = expand_template_em(template, subs)
         # Write the result
         with io.open(template_path, 'w', encoding='utf-8') as f:
-            if sys.version_info.major == 2:
-                result = result.decode('utf-8')
             f.write(result)
         # Copy the permissions
         shutil.copymode(item, template_path)

bloom/util.py

@@ -84,6 +84,25 @@
     to_unicode = str
 
 
+def expand_template_em(template, subs):
+    """
+    Compatibility function for EmPy 3 and 4.
+    EmPy 3: em.expand(template, **kwargs)
+    EmPy 4: em.expand(template, locals=dict)
+    """
+    try:
+        import em
+    except ImportError:
+        error("empy was not detected, please install it.", exit=True)
+
+    try:
+        # Try EmPy 4 API first
+        return em.expand(template, locals=subs)
+    except (TypeError, NameError):
+        # Fall back to EmPy 3 API
+        return em.expand(template, **subs)
+
+
 def flush_stdin():
     try:
         from termios import tcflush, TCIFLUSH

setup.py

@@ -1,6 +1,5 @@
 #!/usr/bin/env python
 
-import sys
 from setuptools import find_packages, setup
 
 
@@ -20,7 +19,7 @@
     install_requires=[
         'catkin_pkg >= 0.4.3',
         'setuptools',
-        'empy < 4',
+        'empy',
         'packaging',
         'python-dateutil',
         'PyYAML',

test/unit_tests/test_generators/test_debian/test_generator.py

@@ -2,9 +2,9 @@
 
 from ....utils.common import redirected_stdio
 
-from bloom.generators.debian.generator import em
 from bloom.generators.debian.generator import get_changelogs
 from bloom.generators.debian.generator import format_description
+from bloom.util import expand_template_em
 
 from catkin_pkg.packages import find_packages
 
@@ -24,7 +24,7 @@ def test_unicode_templating():
         assert 'bad_changelog_pkg' in packages
         chlogs = get_changelogs(packages['bad_changelog_pkg'])
         template = "@(changelog)"
-        em.expand(template, {'changelog': chlogs[0][2]})
+        expand_template_em(template, {'changelog': chlogs[0][2]})
 
 
 def test_format_description():