feat: add export flag to list command (#3780)

libmamba/src/api/list.cpp

@@ -28,6 +28,7 @@ namespace mamba
             bool explicit_ = false;
             bool md5 = false;
             bool canonical = false;
+            bool export_ = false;
         };
 
         struct formatted_pkg
@@ -218,7 +219,13 @@ namespace mamba
                 {
                     if (options.canonical)
                     {
-                        LOG_WARNING << "Option --canonical ignored because of --explicit";
+                        LOG_WARNING
+                            << "Option --canonical ignored because --explicit was also provided.";
+                    }
+                    if (options.export_)
+                    {
+                        LOG_WARNING
+                            << "Option --export ignored because --explicit was also provided.";
                     }
                     for (auto p : packages)
                     {
@@ -234,12 +241,24 @@ namespace mamba
                 }
                 else if (options.canonical)
                 {
+                    if (options.export_)
+                    {
+                        LOG_WARNING
+                            << "Option --export ignored because --canonical was also provided.";
+                    }
                     for (auto p : packages)
                     {
                         std::cout << p.channel << "/" << p.platform << "::" << p.name << "-"
                                   << p.version << "-" << p.build_string << std::endl;
                     }
                 }
+                else if (options.export_)
+                {
+                    for (auto p : packages)
+                    {
+                        std::cout << p.name << "=" << p.version << "=" << p.build_string << std::endl;
+                    }
+                }
                 else
                 {
                     auto requested_specs = prefix_data.history().get_requested_specs_map();
@@ -285,6 +304,7 @@ namespace mamba
         options.explicit_ = config.at("explicit").value<bool>();
         options.md5 = config.at("md5").value<bool>();
         options.canonical = config.at("canonical").value<bool>();
+        options.export_ = config.at("export").value<bool>();
 
         auto channel_context = ChannelContext::make_conda_compatible(config.context());
         detail::list_packages(config.context(), regex, channel_context, std::move(options));

micromamba/src/list.cpp

@@ -53,9 +53,19 @@ init_list_parser(CLI::App* subcom, Configuration& config)
     auto& canonical = config.insert(
         Configurable("canonical", false)
             .group("cli")
-            .description("Output canonical names of packages only. Ignored if --explicit.")
+            .description("Output canonical names of packages only. Ignored if --explicit is also provided."
+            )
     );
     subcom->add_flag("-c,--canonical", canonical.get_cli_config<bool>(), canonical.description());
+
+    auto& export_ = config.insert(
+        Configurable("export", false)
+            .group("cli")
+            .description(
+                "Output explicit, machine-readable requirement strings instead of human-readable lists of packages. Ignored if --explicit or --canonical is also provided."
+            )
+    );
+    subcom->add_flag("-e,--export", export_.get_cli_config<bool>(), export_.description());
 }
 
 void

micromamba/tests/test_list.py

@@ -82,6 +82,7 @@ def test_list_no_json(
 @pytest.mark.parametrize("explicit_flag", ["", "--explicit"])
 @pytest.mark.parametrize("md5_flag", ["", "--md5"])
 @pytest.mark.parametrize("canonical_flag", ["", "-c", "--canonical"])
+@pytest.mark.parametrize("export_flag", ["", "-e", "--export"])
 @pytest.mark.parametrize("env_selector", ["", "name", "prefix"])
 @pytest.mark.parametrize("shared_pkgs_dirs", [True], indirect=True)
 def test_list_subcommands(
@@ -93,28 +94,38 @@ def test_list_subcommands(
     explicit_flag,
     md5_flag,
     canonical_flag,
+    export_flag,
 ):
     if env_selector == "prefix":
-        res = helpers.umamba_list("-p", tmp_xtensor_env, explicit_flag, md5_flag, canonical_flag)
+        res = helpers.umamba_list(
+            "-p", tmp_xtensor_env, explicit_flag, md5_flag, canonical_flag, export_flag
+        )
     elif env_selector == "name":
-        res = helpers.umamba_list("-n", tmp_env_name, explicit_flag, md5_flag, canonical_flag)
+        res = helpers.umamba_list(
+            "-n", tmp_env_name, explicit_flag, md5_flag, canonical_flag, export_flag
+        )
     else:
-        res = helpers.umamba_list(explicit_flag, md5_flag, canonical_flag)
+        res = helpers.umamba_list(explicit_flag, md5_flag, canonical_flag, export_flag)
 
     outputs_list = res.strip().split("\n")[2:]
+    outputs_list = [i for i in outputs_list if i != "" and not i.startswith("Warning")]
+    items = ["conda-forge/", "::"]
     if explicit_flag == "--explicit":
         for output in outputs_list:
             assert "/conda-forge/" in output
             if md5_flag == "--md5":
                 assert "#" in output
             else:
                 assert "#" not in output
-    else:
-        if canonical_flag == "--canonical":
-            items = ["conda-forge/", "::"]
-            for output in outputs_list:
-                assert all(i in output for i in items)
-                assert " " not in output
+    elif canonical_flag in ["-c", "--canonical"]:
+        for output in outputs_list:
+            assert all(i in output for i in items)
+            assert " " not in output
+    elif export_flag in ["-e", "--export"]:
+        items += [" "]
+        for output in outputs_list:
+            assert all(i not in output for i in items)
+            assert len(output.split("=")) == 3
 
 
 @pytest.mark.parametrize("quiet_flag", ["", "-q", "--quiet"])