Implements requirements command as per #4959

Pipfile

@@ -11,6 +11,7 @@ sphinxcontrib-spelling = "<4.3.0"
 
 [scripts]
 tests = "bash ./run-tests.sh"
+test = "pytest -vvs"
 
 [pipenv]
 allow_prereleases = true

README.md

@@ -185,6 +185,9 @@ Magic shell completions are now enabled!
        Use a lower-level pip command:
        $ pipenv run pip freeze
 
+       Generate a requirements.txt file (including dev):
+       $ pipenv reqs --dev > requirements.txt
+
     Commands:
       check      Checks for security vulnerabilities and against PEP 508 markers
                  provided in Pipfile.
@@ -199,6 +202,7 @@ Magic shell completions are now enabled!
                  Pipfile.
       shell      Spawns a shell within the virtualenv.
       sync       Installs all packages specified in Pipfile.lock.
+      reqs       Generates a requirements.txt compatible output directly from Pipfile.lock
       uninstall  Un-installs a provided package and removes it from Pipfile.
 
 Locate the project:

docs/advanced.rst

@@ -199,19 +199,45 @@ development dependencies::
     py==1.4.34
     pytest==3.2.3
 
-Finally, if you wish to generate a requirements file with only the
+If you wish to generate a requirements file with only the
 development requirements you can do that too, using the ``--dev-only``
 flag::
 
     $ pipenv lock -r --dev-only
     py==1.4.34
     pytest==3.2.3
 
+Often, you would want to generate a requirements file based on your current
+environment. However, using pipenv lock -r will still do the locking process which
+could update package versions. To keep the packages as is, use the ``--keep-outdated``
+flag::
+
+    $ pipenv lock -r --keep-outdated
+    chardet==3.0.4
+    requests==2.18.4
+    certifi==2017.7.27.1
+    idna==2.6
+    urllib3==1.22
+
+Note that using this approach, packages newly added to the Pipfile will still be
+included in requirements.txt. If you really want to use Pipfile.lock and
+Pipfile.lock only, you can generate the requirements using::
+    $ pipenv reqs
+    chardet==3.0.4
+    requests==2.18.4
+    certifi==2017.7.27.1
+    idna==2.6
+    urllib3==1.22
+
+This will bypass the locking process completely. As with other commands,
+passing ``--dev`` will include both the default and development dependencies
+
 The locked requirements are written to stdout, with shell output redirection
 used to write them to a file::
 
     $ pipenv lock -r > requirements.txt
     $ pipenv lock -r --dev-only > dev-requirements.txt
+    $ pipenv reqs --dev > all-requirements.txt
     $ cat requirements.txt
     chardet==3.0.4
     requests==2.18.4
@@ -221,7 +247,14 @@ used to write them to a file::
     $ cat dev-requirements.txt
     py==1.4.34
     pytest==3.2.3
-
+    $ cat all-requirements.txt
+    chardet==3.0.4
+    requests==2.18.4
+    certifi==2017.7.27.1
+    idna==2.6
+    urllib3==1.22
+    py==1.4.34
+    pytest==3.2.3
 
 ☤ Detection of Security Vulnerabilities
 ---------------------------------------

news/#4959.feature

@@ -0,0 +1 @@
+Implements a `pipenv reqs` command which generates a requirements.txt compatible output without locking.

pipenv/cli/command.py

@@ -709,5 +709,24 @@ def verify(state):
     sys.exit(0)
 
 
+@cli.command(
+    short_help="Generate a requirements.txt from Pipfile.lock.",
+    context_settings=CONTEXT_SETTINGS,
+)
+@option("--dev", is_flag=True, default=False, help="Also add development requirements.")
+@pass_state
+def reqs(state, dev=False):
+    lockfile = state.project.lockfile_content
+    for i, package_index in enumerate(lockfile['_meta']['sources']):
+        prefix = '-i' if i == 0 else '--extra-index-url'
+        echo(crayons.normal(' '.join([prefix, package_index['url']])))
+    for req_name, value in lockfile['default'].items():
+        echo(crayons.normal(f"{req_name}{value['version']}"))
+    if dev:
+        for req_name, value in lockfile['develop'].items():
+            echo(crayons.normal(f"{req_name}{value['version']}"))
+    sys.exit(0)
+
+
 if __name__ == "__main__":
     cli()

tests/integration/test_reqs.py

@@ -0,0 +1,56 @@
+import pytest
+
+
+@pytest.mark.requirements
+def test_reqs_generates_requirements_from_lockfile(PipenvInstance):
+    with PipenvInstance(chdir=True) as p:
+        packages = ('requests', '2.14.0')
+        dev_packages = ('flask', '0.12.2')
+        with open(p.pipfile_path, 'w') as f:
+            contents = f"""
+            [packages]
+            {packages[0]}= "=={packages[1]}"
+            [dev-packages]
+            {dev_packages[0]}= "=={dev_packages[1]}"
+            """.strip()
+            f.write(contents)
+        p.pipenv('lock')
+        c = p.pipenv('reqs')
+        d = p.pipenv('reqs --dev')
+        assert c.returncode == 0
+        assert d.returncode == 0
+
+        assert f'{packages[0]}=={packages[1]}' in c.stdout
+        assert f'{dev_packages[0]}=={dev_packages[1]}' not in c.stdout
+
+        assert f'{packages[0]}=={packages[1]}' in d.stdout
+        assert f'{dev_packages[0]}=={dev_packages[1]}' in d.stdout
+
+
+@pytest.mark.requirements
+def test_reqs_generates_requirements_from_lockfile_multiple_sources(PipenvInstance):
+    with PipenvInstance(chdir=True) as p:
+        packages = ('requests', '2.14.0')
+        dev_packages = ('flask', '0.12.2')
+        with open(p.pipfile_path, 'w') as f:
+            contents = f"""
+            [[source]]
+            name = "pypi"
+            url = "https://pypi.org/simple"
+            verify_ssl = true
+            [[source]]
+            name = "other_source"
+            url = "https://some_other_source.org"
+            verify_ssl = true
+            [packages]
+            {packages[0]}= "=={packages[1]}"
+            [dev-packages]
+            {dev_packages[0]}= "=={dev_packages[1]}"
+            """.strip()
+            f.write(contents)
+        p.pipenv('lock')
+        c = p.pipenv('reqs')
+        assert c.returncode == 0
+
+        assert '-i https://pypi.org/simple' in c.stdout
+        assert '--extra-index-url https://some_other_source.org' in c.stdout