fix: check if pyproject has poetry earlier

During the evaluation in the package phase, we determine whether a
`requirements.txt` file exists, or whether we need to generate one.

Since the `pyproject.toml` file is used by poetry, but only if a stanza
is contained inside the file, use the function `isPoetryProject()` along
with the configuration value, thereby reducing the need for a project to
have to declare a configuration override.

Refs serverless#324
Refs serverless#344
Fixes serverless#400

Signed-off-by: Mike Fiedler <[email protected]>

Author: miketheman

lib/pip.js

@@ -7,6 +7,7 @@ const { spawnSync } = require('child_process');
 const { quote } = require('shell-quote');
 const { buildImage, getBindPath, getDockerUid } = require('./docker');
 const { getStripCommand, getStripMode, deleteFiles } = require('./slim');
+const { isPoetryProject } = require('./poetry');
 const {
   checkForAndDeleteMaxCacheVersions,
   sha256Path,
@@ -62,7 +63,8 @@ function generateRequirementsFile(
 ) {
   if (
     options.usePoetry &&
-    fse.existsSync(path.join(servicePath, 'pyproject.toml'))
+    fse.existsSync(path.join(servicePath, 'pyproject.toml') &&
+    isPoetryProject(servicePath))
   ) {
     filterRequirementsFile(
       path.join(servicePath, '.serverless/requirements.txt'),
@@ -442,7 +444,8 @@ function copyVendors(vendorFolder, targetFolder, serverless) {
 function requirementsFileExists(servicePath, options, fileName) {
   if (
     options.usePoetry &&
-    fse.existsSync(path.join(servicePath, 'pyproject.toml'))
+    fse.existsSync(path.join(servicePath, 'pyproject.toml') &&
+    isPoetryProject(servicePath))
   ) {
     return true;
   }

lib/poetry.js

@@ -90,4 +90,4 @@ function isPoetryProject(servicePath) {
   return false;
 }
 
-module.exports = { pyprojectTomlToRequirements };
+module.exports = { pyprojectTomlToRequirements, isPoetryProject };

test.js

@@ -744,6 +744,16 @@ test('non build pyproject.toml uses requirements.txt', t => {
   t.end();
 });
 
+test('non poetry pyproject.toml without requirements.txt packages handler only', t => {
+  process.chdir('tests/non_poetry_pyproject');
+  const path = npm(['pack', '../..']);
+  npm(['i', path]);
+  sls(['package']);
+  const zipfiles = listZipFiles('.serverless/sls-py-req-test.zip');
+  t.true(zipfiles.includes(`handler.py`), 'handler is packaged');
+  t.end();
+});
+
 test('poetry py3.6 can package flask with default options', t => {
   process.chdir('tests/poetry');
   const path = npm(['pack', '../..']);