fix: Skip empty lines in environment spec files

Signed-off-by: Julien Jerphanion <git@jjerphan.xyz>

Co-authored-by: Alphonse de Lamartine <alphonse@de-lamartine.fr>

libmamba/src/api/install.cpp

@@ -933,7 +933,13 @@ namespace mamba
                     std::vector<std::string> f_specs;
                     for (auto& line : file_contents)
                     {
-                        if (line[0] != '#' && line[0] != '@')
+                        // Skip comment lines and empty lines
+                        // Comment lines start with '#' or '@' preceded by whitespaces or tabs
+                        auto is_comment = util::starts_with(line, "#")
+                                          || util::starts_with(line, "@");
+                        auto is_empty = std::all_of(line.begin(), line.end(), ::isspace);
+
+                        if (!is_comment && !is_empty)
                         {
                             f_specs.push_back(line);
                         }

micromamba/tests/test_create.py

@@ -1441,3 +1441,30 @@ def test_create_empty_or_absent_dependencies(tmp_path):
         "-p", env_prefix, "-f", tmp_path / "env_spec_absent_dependencies.yaml", "--json"
     )
     assert res["success"]
+
+
+env_spec_empty_lines_and_comments = """
+# The line below are empty (various number of spaces)
+"""
+
+env_spec_empty_lines_and_comments += "\n"
+env_spec_empty_lines_and_comments += "  \n"
+env_spec_empty_lines_and_comments += "    \n"
+env_spec_empty_lines_and_comments += "	\n"
+env_spec_empty_lines_and_comments += "# Un seul check vous manque, \n"
+env_spec_empty_lines_and_comments += "@ et tout est explosé\n"
+env_spec_empty_lines_and_comments += "numpy\n"
+
+
+def test_create_with_empty_lines_and_comments(tmp_path):
+    # Non-regression test for
+
+    env_prefix = tmp_path / "env-one_empty_line"
+
+    env_spec = tmp_path / "env_spec_with_one_empty_line.txt"
+
+    with open(env_spec, "w") as f:
+        f.write(env_spec_empty_lines_and_comments)
+
+    res = helpers.create("-p", env_prefix, "-f", env_spec, "--json")
+    assert res["success"]