Fix ordering of format controls to preserve behavior of pip

piptools/writer.py

@@ -148,9 +148,27 @@ def write_trusted_hosts(self) -> Iterator[str]:
                 yield f"--trusted-host {trusted_host}"
 
     def write_format_controls(self) -> Iterator[str]:
-        for nb in dedup(sorted(self.format_control.no_binary)):
+        # The ordering of output needs to preserve the behavior of pip's
+        # FormatControl.get_allowed_formats(). The behavior is the following:
+        #
+        #   * Parsing of CLI options happens first to last.
+        #   * --only-binary takes precedence over --no-binary
+        #   * Package names take precedence over :all:
+        #   * We'll never see :all: in both due to mutual exclusion.
+        #
+        # So in summary, we want to emit :all: first and then package names later.
+        no_binary = self.format_control.no_binary.copy()
+        only_binary = self.format_control.only_binary.copy()
+
+        if ":all:" in no_binary:
+            yield "--no-binary :all:"
+            no_binary.remove(":all:")
+        if ":all:" in only_binary:
+            yield "--only-binary :all:"
+            only_binary.remove(":all:")
+        for nb in dedup(sorted(no_binary)):
             yield f"--no-binary {nb}"
-        for ob in dedup(sorted(self.format_control.only_binary)):
+        for ob in dedup(sorted(only_binary)):
             yield f"--only-binary {ob}"
 
     def write_find_links(self) -> Iterator[str]:

tests/test_writer.py

@@ -301,6 +301,41 @@ def test_write_format_controls(writer):
     assert lines == expected_lines
 
 
+@pytest.mark.parametrize(
+    ("no_binary", "only_binary", "expected_lines"),
+    (
+        (
+            [":all:"],
+            ["django"],
+            [
+                "--no-binary :all:",
+                "--only-binary django",
+            ],
+        ),
+        (
+            ["django"],
+            [":all:"],
+            [
+                "--only-binary :all:",
+                "--no-binary django",
+            ],
+        ),
+    ),
+)
+def test_write_format_controls_all(writer, no_binary, only_binary, expected_lines):
+    """
+    Tests --no-binary/--only-binary options
+    with the value of :all:. We want to preserve
+    the FormatControl behavior so we emit :all:
+    first before packages.
+    """
+
+    writer.format_control = FormatControl(no_binary=no_binary, only_binary=only_binary)
+    lines = list(writer.write_format_controls())
+
+    assert lines == expected_lines
+
+
 @pytest.mark.parametrize(
     ("index_urls", "expected_lines"),
     (