tools/ci.sh: Allow CI tests to run locally.

When working on code in this repo, it can be beneficial to run the same
tests that run as part of the CI workflow on GitHub.

This change makes it possible to run `tools/ci.sh` without it messing
with your user-wide micropython install (`~/.micropython/lib`). It now
defaults to creating a virtual environment in `/tmp/micropython-venv`.

Expected usage of this is:
```bash
# Setup tests (run once)
$ source tools/ci.sh
$ ci_package_tests_setup_micropython
# Run tests (run many times)
$ ci_package_tests_setup_lib && ci_package_tests_run || echo 'Failed'
```

Signed-off-by: Greg Darke <micropython@me.tsukasa.au>

Author: tsukasa-au

tools/ci.sh

@@ -17,7 +17,9 @@ function ci_commit_formatting_run {
 ########################################################################################
 # package tests
 
-MICROPYTHON=/tmp/micropython/ports/unix/build-standard/micropython
+VIRTUAL_ENV="${VIRTUAL_ENV:-/tmp/micropython-venv}"
+MICROPYTHON="${MICROPYTHON:-${VIRTUAL_ENV}/bin/micropython}"
+MICROPYPATH="${VIRTUAL_ENV}/lib:.frozen"
 
 function ci_package_tests_setup_micropython {
     git clone https://github.com/micropython/micropython.git /tmp/micropython
@@ -26,26 +28,32 @@ function ci_package_tests_setup_micropython {
     make -C /tmp/micropython/mpy-cross -j CFLAGS_EXTRA=-O0
     make -C /tmp/micropython/ports/unix submodules
     make -C /tmp/micropython/ports/unix -j CFLAGS_EXTRA=-O0
+
+    # Create the virtual environment directory
+    mkdir -p "${VIRTUAL_ENV}/bin" "${VIRTUAL_ENV}/lib"
+    ln -s /tmp/micropython/ports/unix/build-standard/micropython "${MICROPYTHON}"
 }
 
 function ci_package_tests_setup_lib {
-    mkdir -p ~/.micropython/lib
-    $CP micropython/ucontextlib/ucontextlib.py ~/.micropython/lib/
-    $CP python-stdlib/fnmatch/fnmatch.py ~/.micropython/lib/
-    $CP -r python-stdlib/hashlib-core/hashlib ~/.micropython/lib/
-    $CP -r python-stdlib/hashlib-sha224/hashlib ~/.micropython/lib/
-    $CP -r python-stdlib/hashlib-sha256/hashlib ~/.micropython/lib/
-    $CP -r python-stdlib/hashlib-sha384/hashlib ~/.micropython/lib/
-    $CP -r python-stdlib/hashlib-sha512/hashlib ~/.micropython/lib/
-    $CP python-stdlib/shutil/shutil.py ~/.micropython/lib/
-    $CP python-stdlib/tempfile/tempfile.py ~/.micropython/lib/
-    $CP -r python-stdlib/unittest/unittest ~/.micropython/lib/
-    $CP -r python-stdlib/unittest-discover/unittest ~/.micropython/lib/
-    $CP unix-ffi/ffilib/ffilib.py ~/.micropython/lib/
-    tree ~/.micropython
+    export MICROPYPATH
+    mkdir -p ${VIRTUAL_ENV}/lib
+    $CP micropython/ucontextlib/ucontextlib.py ${VIRTUAL_ENV}/lib/
+    $CP python-stdlib/fnmatch/fnmatch.py ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/hashlib-core/hashlib ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/hashlib-sha224/hashlib ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/hashlib-sha256/hashlib ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/hashlib-sha384/hashlib ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/hashlib-sha512/hashlib ${VIRTUAL_ENV}/lib/
+    $CP python-stdlib/shutil/shutil.py ${VIRTUAL_ENV}/lib/
+    $CP python-stdlib/tempfile/tempfile.py ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/unittest/unittest ${VIRTUAL_ENV}/lib/
+    $CP -r python-stdlib/unittest-discover/unittest ${VIRTUAL_ENV}/lib/
+    $CP unix-ffi/ffilib/ffilib.py ${VIRTUAL_ENV}/lib/
+    tree ${VIRTUAL_ENV}
 }
 
 function ci_package_tests_run {
+    export MICROPYPATH
     for test in \
         micropython/drivers/storage/sdcard/sdtest.py \
         micropython/xmltok/test_xmltok.py \