GH-406 (#407)

docs/sections/user_guide/cli/mode_template.rst

@@ -273,7 +273,7 @@ The examples in this section use atparse-formatted template file ``atparse.txt``
   .. code-block:: text
 
      $ uw template translate --input-file atparse.txt
-     {{greeting}}, {{recipient}}!
+     {{ greeting }}, {{ recipient }}!
 
   Shell redirection via ``|``, ``>``, et al. may also be used to stream output to a file, another process, etc.
 
@@ -287,11 +287,11 @@ The examples in this section use atparse-formatted template file ``atparse.txt``
 
   .. code-block:: jinja
 
-     {{greeting}}, {{recipient}}!
+     {{ greeting }}, {{ recipient }}!
 
 * With the ``--dry-run`` flag specified, nothing is written to ``stdout`` (or to a file if ``--output-file`` is specified), but a report of what would have been written is logged to ``stderr``:
 
   .. code-block:: text
 
      $ uw template translate --input-file atparse.txt --dry-run
-     [2024-01-03T16:41:13]     INFO {{greeting}}, {{recipient}}!
+     [2024-02-06T21:53:43]     INFO {{ greeting }}, {{ recipient }}!

src/uwtools/config/atparse_to_jinja2.py

@@ -3,7 +3,6 @@
 """
 
 import re
-from typing import IO, Any, Generator
 
 from uwtools.logging import log
 from uwtools.utils.file import OptionalPath, readable, writable
@@ -23,21 +22,15 @@ def convert(
     :param dry_run: Run in dry-run mode?
     """
 
-    def lines() -> Generator[str, Any, Any]:
-        with readable(input_file) as f_in:
-            for line in f_in.read().strip().split("\n"):
-                yield _replace(line.strip())
-
-    def write(f_out: IO) -> None:
-        for line in lines():
-            print(_replace(line.strip()), file=f_out)
-
+    with readable(input_file) as f:
+        lines = f.readlines()
+    jinja2 = "".join(_replace(line) for line in lines)
     if dry_run:
-        for line in lines():
+        for line in jinja2.removesuffix("\n").split("\n"):
             log.info(line)
     else:
         with writable(output_file) as f:
-            write(f)
+            f.write(jinja2)
 
 
 def _replace(atline: str) -> str:
@@ -54,5 +47,5 @@ def _replace(atline: str) -> str:
         # Set maxsplits to 1 so only first ] is captured, which should be the
         # bracket closing @[.
         after_atparse = atline.split("@[", 1)[1].split("]", 1)[1]
-        atline = "".join([before_atparse, "{{", within_atparse, "}}", after_atparse])
+        atline = "".join([before_atparse, "{{ ", within_atparse, " }}", after_atparse])
     return atline

src/uwtools/tests/config/test_atparse_to_jinja2.py

@@ -18,83 +18,118 @@
 
 
 @fixture
-def atparselines():
-    return ["@[greeting] to the @[subject]", "@[flowers] are @[color]"]
+def txt_atparse():
+    return """
+@[greeting] to the @[subject]
+@[flowers] are @[color]
+""".strip()
 
 
 @fixture
-def atparsefile(atparselines, tmp_path):
-    path = tmp_path / "atparse.txt"
-    with open(path, "w", encoding="utf-8") as f:
-        for line in atparselines:
-            print(line, file=f)
-    return path
+def txt_jinja2():
+    return """
+{{ greeting }} to the {{ subject }}
+{{ flowers }} are {{ color }}
+""".strip()
 
 
 @fixture
-def jinja2txt():
-    return "{{greeting}} to the {{subject}}\n{{flowers}} are {{color}}\n"
+def atparsefile(txt_atparse, tmp_path):
+    path = tmp_path / "atparse.txt"
+    with open(path, "w", encoding="utf-8") as f:
+        print(txt_atparse, file=f)
+    return path
 
 
 # Test functions
 
 
-def test_convert_input_file_to_output_file(atparsefile, capsys, jinja2txt, tmp_path):
+def test_convert_input_file_to_output_file(atparsefile, capsys, txt_jinja2, tmp_path):
     outfile = tmp_path / "outfile"
     atparse_to_jinja2.convert(input_file=atparsefile, output_file=outfile)
     with open(outfile, "r", encoding="utf-8") as f:
-        assert f.read() == jinja2txt
+        assert f.read().strip() == txt_jinja2
     streams = capsys.readouterr()
     assert not streams.err
     assert not streams.out
 
 
-def test_convert_input_file_to_logging(atparsefile, caplog, capsys, jinja2txt, tmp_path):
+def test_convert_input_file_to_logging(atparsefile, caplog, capsys, txt_jinja2, tmp_path):
     log.setLevel(logging.INFO)
     outfile = tmp_path / "outfile"
     atparse_to_jinja2.convert(input_file=atparsefile, dry_run=True)
     streams = capsys.readouterr()
-    assert "\n".join(record.message for record in caplog.records) == jinja2txt.strip()
+    assert "\n".join(record.message for record in caplog.records).strip() == txt_jinja2
     assert not streams.out
     assert not outfile.is_file()
 
 
-def test_convert_input_file_to_stdout(atparsefile, capsys, jinja2txt):
+def test_convert_input_file_to_stdout(atparsefile, capsys, txt_jinja2):
     atparse_to_jinja2.convert(input_file=atparsefile)
     streams = capsys.readouterr()
     assert not streams.err
-    assert streams.out == jinja2txt
+    assert streams.out.strip() == txt_jinja2
+
+
+def test_convert_preserve_whitespace(tmp_path):
+    atparse = """
+
+@[first_entry]
+  @[second_entry]
+  @[third_entry]
+    @[fourth_entry]
+
+        @[fifth_entry] @[sixth_entry]
+
+"""
+    infile = tmp_path / "atparse"
+    with open(infile, "w", encoding="utf-8") as f:
+        f.write(atparse)
+    outfile = tmp_path / "jinja2"
+    atparse_to_jinja2.convert(input_file=infile, output_file=outfile)
+    expected = """
+
+{{ first_entry }}
+  {{ second_entry }}
+  {{ third_entry }}
+    {{ fourth_entry }}
+
+        {{ fifth_entry }} {{ sixth_entry }}
+
+"""
+    with open(outfile, "r", encoding="utf-8") as f:
+        assert f.read() == expected
 
 
-def test_convert_stdin_to_file(atparselines, capsys, jinja2txt, tmp_path):
+def test_convert_stdin_to_file(txt_atparse, capsys, txt_jinja2, tmp_path):
     outfile = tmp_path / "outfile"
     _stdinproxy.cache_clear()
-    with patch.object(sys, "stdin", new=StringIO("\n".join(atparselines))):
+    with patch.object(sys, "stdin", new=StringIO(txt_atparse)):
         atparse_to_jinja2.convert(output_file=outfile)
     with open(outfile, "r", encoding="utf-8") as f:
-        assert f.read() == jinja2txt
+        assert f.read().strip() == txt_jinja2
     streams = capsys.readouterr()
     assert not streams.err
     assert not streams.out
 
 
-def test_convert_stdin_to_logging(atparselines, caplog, jinja2txt, tmp_path):
+def test_convert_stdin_to_logging(txt_atparse, caplog, txt_jinja2, tmp_path):
     log.setLevel(logging.INFO)
     outfile = tmp_path / "outfile"
     _stdinproxy.cache_clear()
-    with patch.object(sys, "stdin", new=StringIO("\n".join(atparselines))):
+    with patch.object(sys, "stdin", new=StringIO(txt_atparse)):
         atparse_to_jinja2.convert(output_file=outfile, dry_run=True)
-    assert "\n".join(record.message for record in caplog.records) == jinja2txt.strip()
+    assert "\n".join(record.message for record in caplog.records) == txt_jinja2
     assert not outfile.is_file()
 
 
-def test_convert_stdin_to_stdout(atparselines, capsys, jinja2txt):
+def test_convert_stdin_to_stdout(txt_atparse, capsys, txt_jinja2):
     _stdinproxy.cache_clear()
-    with patch.object(sys, "stdin", new=StringIO("\n".join(atparselines))):
+    with patch.object(sys, "stdin", new=StringIO(txt_atparse)):
         atparse_to_jinja2.convert()
     streams = capsys.readouterr()
     assert not streams.err
-    assert streams.out == jinja2txt
+    assert streams.out.strip() == txt_jinja2
 
 
 def test__replace():
@@ -103,4 +138,4 @@ def test__replace():
     assert atparse_to_jinja2._replace(line_without) == line_without
     # A line with atparse syntax should be returned updated to Jinja2 syntax:
     line_with = "@[greeting] to the @[subject]"
-    assert atparse_to_jinja2._replace(line_with) == "{{greeting}} to the {{subject}}"
+    assert atparse_to_jinja2._replace(line_with) == "{{ greeting }} to the {{ subject }}"