Add machine readable --list output (#1592)

* Add machine readable --list output

* Refactor list_journals()

Create three new methods for each journal list format.
- JSON, YAML, STDOUT

* Added journal list export test

* Update test regex to handle windows filepaths

3 files changed, 46 insertions, 9 deletions

diff --git a/jrnl/args.py b/jrnl/args.py
index 4b2ba8ce..c6b0f1a0 100644
--- a/jrnl/args.py
+++ b/jrnl/args.py
@@ -85,7 +85,13 @@ def parse_args(args=[]):
         action="store_const",
         const=postconfig_list,
         dest="postconfig_cmd",
-        help="List all configured journals",
+        help="""
+        List all configured journals.
+
+        Optional parameters:
+
+        --format [json or yaml]
+        """,
     )
     standalone.add_argument(
         "--ls",
diff --git a/jrnl/commands.py b/jrnl/commands.py
index a96a2956..6100422b 100644
--- a/jrnl/commands.py
+++ b/jrnl/commands.py
@@ -56,10 +56,10 @@ def preconfig_version(_):
     print(output)
 
 
-def postconfig_list(config, **kwargs):
+def postconfig_list(args, config, **kwargs):
     from jrnl.output import list_journals
 
-    print(list_journals(config))
+    print(list_journals(config, args.export))
 
 
 def postconfig_import(args, config, **kwargs):
diff --git a/jrnl/output.py b/jrnl/output.py
index b82ec122..2db0362e 100644
--- a/jrnl/output.py
+++ b/jrnl/output.py
@@ -25,19 +25,50 @@ def deprecated_cmd(old_cmd, new_cmd, callback=None, **kwargs):
         callback(**kwargs)
 
 
-def list_journals(configuration):
-    from jrnl import config
+def journal_list_to_json(journal_list):
+    import json
 
-    """List the journals specified in the configuration file"""
-    result = f"Journals defined in config ({config.get_config_path()})\n"
-    ml = min(max(len(k) for k in configuration["journals"]), 20)
-    for journal, cfg in configuration["journals"].items():
+    return json.dumps(journal_list)
+
+
+def journal_list_to_yaml(journal_list):
+    from io import StringIO
+
+    from ruamel.yaml import YAML
+
+    output = StringIO()
+    YAML().dump(journal_list, output)
+    return output.getvalue()
+
+
+def journal_list_to_stdout(journal_list):
+    result = f"Journals defined in config ({journal_list['config_path']})\n"
+    ml = min(max(len(k) for k in journal_list["journals"]), 20)
+    for journal, cfg in journal_list["journals"].items():
         result += " * {:{}} -> {}\n".format(
             journal, ml, cfg["journal"] if isinstance(cfg, dict) else cfg
         )
     return result
 
 
+def list_journals(configuration, format=None):
+    from jrnl import config
+
+    """List the journals specified in the configuration file"""
+
+    journal_list = {
+        "config_path": config.get_config_path(),
+        "journals": configuration["journals"],
+    }
+
+    if format == "json":
+        return journal_list_to_json(journal_list)
+    elif format == "yaml":
+        return journal_list_to_yaml(journal_list)
+    else:
+        return journal_list_to_stdout(journal_list)
+
+
 def print_msg(msg: Message, **kwargs) -> Union[None, str]:
     """Helper function to print a single message"""
     kwargs["style"] = msg.style