Add --dry-run option to version command

Resolves: #5074

docs/cli.md

@@ -623,6 +623,7 @@ The table below illustrates the effect of these rules with concrete examples.
 ### Options
 ### Options
 
 
 * `--short (-s)`: Output the version number only.
 * `--short (-s)`: Output the version number only.
+* `--dry-run`: Do not update pyproject.toml file.
 
 
 ## export
 ## export
 
 

src/poetry/console/commands/version.py

@@ -29,7 +29,14 @@ class VersionCommand(Command):
             optional=True,
             optional=True,
         )
         )
     ]
     ]
-    options = [option("short", "s", "Output the version number only")]
+    options = [
+        option("short", "s", "Output the version number only"),
+        option(
+            "dry-run",
+            None,
+            "Do not update pyproject.toml file",
+        ),
+    ]
 
 
     help = """\
     help = """\
 The version command shows the current version of the project or bumps the version of
 The version command shows the current version of the project or bumps the version of
@@ -66,12 +73,13 @@ patch, minor, major, prepatch, preminor, premajor, prerelease.
                     f" to <fg=green>{version}</>"
                     f" to <fg=green>{version}</>"
                 )
                 )
 
 
-            content: dict[str, Any] = self.poetry.file.read()
-            poetry_content = content["tool"]["poetry"]
-            poetry_content["version"] = version.text
+            if not self.option("dry-run"):
+                content: dict[str, Any] = self.poetry.file.read()
+                poetry_content = content["tool"]["poetry"]
+                poetry_content["version"] = version.text
 
 
-            assert isinstance(content, TOMLDocument)
-            self.poetry.file.write(content)
+                assert isinstance(content, TOMLDocument)
+                self.poetry.file.write(content)
         else:
         else:
             if self.option("short"):
             if self.option("short"):
                 self.line(self.poetry.package.pretty_version)
                 self.line(self.poetry.package.pretty_version)

tests/console/commands/test_version.py

@@ -76,3 +76,12 @@ def test_version_update(tester: CommandTester):
 def test_short_version_update(tester: CommandTester):
 def test_short_version_update(tester: CommandTester):
     tester.execute("--short 2.0.0")
     tester.execute("--short 2.0.0")
     assert tester.io.fetch_output() == "2.0.0\n"
     assert tester.io.fetch_output() == "2.0.0\n"
+
+
+def test_dry_run(tester: CommandTester):
+    old_pyproject = tester.command.poetry.file.path.read_text()
+    tester.execute("--dry-run major")
+
+    new_pyproject = tester.command.poetry.file.path.read_text()
+    assert tester.io.fetch_output() == "Bumping version from 1.2.3 to 2.0.0\n"
+    assert old_pyproject == new_pyproject