Support python console REPL.

README.md

@@ -154,3 +154,35 @@ The following gives an error:
 ````
 
 The keyword `expect-exception` is also possible.
+
+#### Doctest-style code blocks
+
+Code blocks starting with `">>>"` will be treated as interactive Python shell code, and tested by [doctest](https://docs.python.org/3/library/doctest.html).
+
+````markdown
+```python
+>>> print("Hello")
+Hello
+>>> 2+3
+5
+```
+````
+You can concatenate multiple doctest-style code blocks with `<!--pytest-codeblocks:cont-->`, but cannot mix doctest-style ones with normal python code blocks, or vice versa.
+
+There are two ways to indicate expected exceptions in doctest-style code blocks. One is to include the expected exception into you code block, and let doctest handle it. 
+
+````markdown
+```python
+>>> raise Exception("This should fail")
+Traceback (most recent call last):
+  File "<stdin>", line 1, in <module>
+Exception: This should fail
+```
+````
+The other way is to use the `<!--pytest-codeblocks:expect-exception-->`, and let pytest handle it.
+````markdown
+<!--pytest-codeblocks:expect-exception-->
+```python
+>>> raise Exception("This should fail")
+```
+````

src/pytest_codeblocks/main.py

@@ -7,9 +7,13 @@
 # namedtuple with default arguments
 # <https://stackoverflow.com/a/18348004/353337>
 from dataclasses import dataclass
+from doctest import DebugRunner, DocTestFinder
 from io import StringIO
 from pathlib import Path
 
+finder = DocTestFinder()
+runner = DebugRunner()
+
 
 @dataclass
 class CodeBlock:
@@ -21,6 +25,13 @@ class CodeBlock:
     skip: bool = False
     skipif: str | None = None
 
+    def exec(self, globs: dict) -> None:
+        if self.code.startswith(">>>"):
+            for test in finder.find(self.code, name=f"line {self.lineno}", globs=globs):
+                runner.run(test)
+        else:
+            exec(self.code, globs)
+
 
 def extract_from_file(
     f: str | bytes | Path, encoding: str | None = "utf-8", *args, **kwargs

src/pytest_codeblocks/plugin.py

@@ -64,12 +64,12 @@ def runtest(self):
         if self.obj.syntax == "python":
             if self.obj.expect_exception:
                 with pytest.raises(Exception):
-                    exec(self.obj.code, {"__MODULE__": "__main__"})
+                    self.obj.exec({"__MODULE__": "__main__"})
             else:
                 with stdout_io() as s:
                     try:
                         # https://stackoverflow.com/a/62851176/353337
-                        exec(self.obj.code, {"__MODULE__": "__main__"})
+                        self.obj.exec({"__MODULE__": "__main__"})
                     except Exception as e:
                         raise RuntimeError(
                             f"{self.name}, line {self.obj.lineno}:\n```\n"

tests/test_repl.py

@@ -0,0 +1,56 @@
+import pathlib
+
+from pytest import skip
+
+import pytest_codeblocks
+
+
+def test_repr(testdir):
+    string1 = """
+    ```python
+    >>> print("Hello World!")
+    Hello World!
+    ```
+    """
+    testdir.makefile(".md", string1)
+    result = testdir.runpytest("--codeblocks")
+    result.assert_outcomes(passed=1)
+
+
+def test_cont(testdir):
+    string1 = """
+    ```python
+    >>> def add(a, b):
+    ...     return a + b
+    ```
+
+    <!--pytest-codeblocks:cont-->
+    ```python
+    >>> add(2,7)
+    9
+    ```
+    """
+    testdir.makefile(".md", string1)
+    result = testdir.runpytest("--codeblocks")
+    result.assert_outcomes(passed=1)
+
+
+def test_exception(testdir):
+    string1 = """
+    Handle the exception by doctest:
+    ```python
+    >>> raise Exception("This should fail")
+    Traceback (most recent call last):
+      File "<stdin>", line 1, in <module>
+    Exception: This should fail
+    ```
+
+    Handle the exception by pytest:
+    <!--pytest-codeblocks:expect-exception-->
+    ```python
+    >>> raise Exception("This should fail")
+    ```
+    """
+    testdir.makefile(".md", string1)
+    result = testdir.runpytest("--codeblocks")
+    result.assert_outcomes(passed=2)