sources: deprecate priority 'default'

docs/repositories.md

@@ -126,9 +126,9 @@ priority = "primary"
 If `priority` is undefined, the source is considered a primary source that takes precedence over PyPI, secondary, supplemental and explicit sources.
 
 Package sources are considered in the following order:
-1. [default source](#default-package-source),
+1. [default source](#default-package-source-deprecated) (DEPRECATED),
 2. [primary sources](#primary-package-sources),
-3. implicit PyPI (unless disabled by another [primary source](#primary-package-sources), [default source](#default-package-source) or configured explicitly),
+3. implicit PyPI (unless disabled by another [primary source](#primary-package-sources), [default source](#default-package-source-deprecated) or configured explicitly),
 4. [secondary sources](#secondary-package-sources-deprecated) (DEPRECATED),
 5. [supplemental sources](#supplemental-package-sources).
 
@@ -145,20 +145,29 @@ poetry source add --priority=primary PyPI
 ```
 
 If you prefer to disable PyPI completely,
-you may choose to set one of your package sources to be the [default](#default-package-source),
 just add a [primary source](#primary-package-sources)
 or configure PyPI as [explicit source](#explicit-package-sources).
 
 {{% /note %}}
 
 
-#### Default Package Source
+#### Default Package Source (DEPRECATED)
+
+*Deprecated in 1.8.0*
+
+{{% warning %}}
+
+Configuring a default package source is deprecated because it is the same
+as the topmost [primary source](#primary-package-sources).
+Just configure a primary package source and put it first in the list of package sources.
+
+{{% /warning %}}
 
 By default, if you have not configured any primary source,
 Poetry will configure [PyPI](https://pypi.org) as the package source for your project.
 You can alter this behaviour and exclusively look up packages only from the configured
-package sources by adding at least one primary source
-or a **single** source with `priority = "default"`.
+package sources by adding at least one primary source (recommended)
+or a **single** source with `priority = "default"` (deprecated).
 
 ```bash
 poetry source add --priority=default foo https://foo.bar/simple/

src/poetry/console/commands/source/add.py

@@ -107,12 +107,20 @@ def handle(self) -> int:
             priority = Priority[priority_str.upper()]
 
         if priority is Priority.SECONDARY:
-            allowed_prios = (p for p in Priority if p is not Priority.SECONDARY)
+            allowed_prios = (
+                p for p in Priority if p not in {Priority.DEFAULT, Priority.SECONDARY}
+            )
             self.line_error(
                 "<warning>Warning: Priority 'secondary' is deprecated. Consider"
                 " changing the priority to one of the non-deprecated values:"
                 f" {', '.join(repr(p.name.lower()) for p in allowed_prios)}.</warning>"
             )
+        if priority is Priority.DEFAULT:
+            self.line_error(
+                "<warning>Warning: Priority 'default' is deprecated. You can achieve"
+                " the same effect by changing the priority to 'primary' and putting"
+                " the source first.</warning>"
+            )
 
         sources = AoT([])
         new_source = Source(name=name, url=url, priority=priority)

src/poetry/factory.py

@@ -159,6 +159,14 @@ def create_pool(
                     f" {', '.join(repr(p.name.lower()) for p in allowed_prios)}."
                 )
                 io.write_error_line(f"<warning>Warning: {warning}</warning>")
+            elif priority is Priority.DEFAULT:
+                warning = (
+                    "Found deprecated priority 'default' for source"
+                    f" '{source.get('name')}' in pyproject.toml. You can achieve"
+                    " the same effect by changing the priority to 'primary' and putting"
+                    " the source first."
+                )
+                io.write_error_line(f"<warning>Warning: {warning}</warning>")
 
             if io.is_debug():
                 message = f"Adding repository {repository.name} ({repository.url})"

tests/console/commands/source/test_add.py

@@ -22,27 +22,34 @@ def tester(
     return command_tester_factory("source add", poetry=poetry_with_source)
 
 
+def _get_source_warning(priority: Priority) -> str:
+    if priority is Priority.SECONDARY:
+        return (
+            "Warning: Priority 'secondary' is deprecated. Consider changing the"
+            " priority to one of the non-deprecated values: 'primary',"
+            " 'supplemental', 'explicit'."
+        )
+    elif priority is Priority.DEFAULT:
+        return (
+            "Warning: Priority 'default' is deprecated. You can achieve"
+            " the same effect by changing the priority to 'primary' and putting"
+            " the source first."
+        )
+    return ""
+
+
 def assert_source_added_legacy(
     tester: CommandTester,
     poetry: Poetry,
     source_existing: Source,
     source_added: Source,
 ) -> None:
-    secondary_deprecated_str = (
-        ""
-        if source_added.priority is not Priority.SECONDARY
-        else (
-            "\nWarning: Priority 'secondary' is deprecated. Consider changing the"
-            " priority to one of the non-deprecated values: 'default', 'primary',"
-            " 'supplemental', 'explicit'."
-        )
-    )
-    assert (
-        tester.io.fetch_error().strip()
-        == "Warning: Priority was set through a deprecated flag (--default or"
-        " --secondary). Consider using --priority next time."
-        + secondary_deprecated_str
+    warning = (
+        "Warning: Priority was set through a deprecated flag (--default or"
+        " --secondary). Consider using --priority next time.\n"
+        + _get_source_warning(source_added.priority)
     )
+    assert tester.io.fetch_error().strip() == warning
     assert (
         tester.io.fetch_output().strip()
         == f"Adding source with name {source_added.name}."
@@ -59,6 +66,7 @@ def assert_source_added(
     source_existing: Source,
     source_added: Source,
 ) -> None:
+    assert tester.io.fetch_error().strip() == _get_source_warning(source_added.priority)
     assert (
         tester.io.fetch_output().strip()
         == f"Adding source with name {source_added.name}."
@@ -126,9 +134,9 @@ def test_source_add_second_default_fails(
     tester.execute(f"--priority=default {source_default.name}1 {source_default.url}")
     assert (
         tester.io.fetch_error().strip()
-        == f"Source with name {source_default.name} is already set to"
-        " default. Only one default source can be configured at a"
-        " time."
+        == f"{_get_source_warning(source_default.priority)}\n"
+        f"Source with name {source_default.name} is already set to default."
+        " Only one default source can be configured at a time."
     )
     assert tester.status_code == 1
 
@@ -238,7 +246,7 @@ def test_source_add_existing_legacy(
         tester.io.fetch_error().strip()
         == "Warning: Priority was set through a deprecated flag"
         " (--default or --secondary). Consider using --priority next"
-        " time."
+        f" time.\n{_get_source_warning(Priority.DEFAULT)}"
     )
     assert (
         tester.io.fetch_output().strip()
@@ -313,16 +321,17 @@ def test_source_add_existing_fails_due_to_other_default(
     poetry_with_source: Poetry,
 ) -> None:
     tester.execute(f"--priority=default {source_default.name} {source_default.url}")
+    tester.io.fetch_error()
     tester.io.fetch_output()
 
     name = getattr(source_existing.name, modifier)()
     tester.execute(f"--priority=default {name} {source_existing.url}")
 
     assert (
         tester.io.fetch_error().strip()
-        == f"Source with name {source_default.name} is already set to"
-        " default. Only one default source can be configured at a"
-        " time."
+        == f"{_get_source_warning(source_default.priority)}\n"
+        f"Source with name {source_default.name} is already set to default."
+        " Only one default source can be configured at a time."
     )
     assert tester.io.fetch_output().strip() == ""
     assert tester.status_code == 1

tests/test_factory.py

@@ -241,7 +241,12 @@ def test_poetry_with_default_source(
     poetry = Factory().create_poetry(fixture_dir("with_default_source"), io=io)
 
     assert len(poetry.pool.repositories) == 1
-    assert io.fetch_error() == ""
+    assert (
+        io.fetch_error().strip()
+        == "<warning>Warning: Found deprecated priority 'default' for source 'foo' in"
+        " pyproject.toml. You can achieve the same effect by changing the priority"
+        " to 'primary' and putting the source first."
+    )
 
 
 def test_poetry_with_default_source_and_pypi(