chore: fix regression tests (aws#8054)

The new-style integ tests don't run under the current regression test
framework. 2 changes:

1. The regression tests were downloading the repository SOURCE from
GitHub. That was fine as long as the tests were bash scripts (because
source == artifact there), but now the tests are compiled, so we need to
get the built artifacts (i.e., NPM package).

(This is also more efficient as there will be less to download)

2. Because of the specific arguments to jest (all regexes instead of
relative paths) and how it was being run, `jest` was finding and running
multiple copies of the tests, but only one had been bootstrapped so for
the other copy, `aws-sdk` was not found and the tests would error.

Introduce a `jest.config.js` so that jest will treat the
`test/integ/cli` directory as the root for tests and won't search
elsewhere. Put as much config into it as possible if we've got it
anyway (notably: `--runInBand` seems not to be able to go in there).

Since the regression test are going to run the tests from the PREVIOUS
version (which still has the bug), hotpatch the new test runner
config over the old one (but be sure to leave the actual tests the
same).

packages/aws-cdk/.gitignore

@@ -32,3 +32,4 @@ cdk.context.json
 # as the subdirs contain .js files that should be committed)
 test/integ/cli/*.js
 test/integ/cli/*.d.ts
+!test/integ/cli/jest.config.js

packages/aws-cdk/test/integ/cli/jest.config.js

@@ -0,0 +1,11 @@
+module.exports = {
+    moduleFileExtensions: [
+        "js",
+    ],
+    testMatch: [
+        "**/*.integtest.js",
+    ],
+    testEnvironment: "node",
+    bail: 1,
+    verbose: true,
+};

packages/aws-cdk/test/integ/cli/test-jest.sh

@@ -16,4 +16,4 @@ if ! npx --no-install jest --version; then
   npm install --prefix . jest aws-sdk
 fi
 
-npx jest --runInBand --testPathPattern 'test/integ/cli' --testMatch '**/*.integtest.js' --verbose "$@"
+npx jest --runInBand --verbose "$@"

packages/aws-cdk/test/integ/test-cli-regression-against-current-code.sh

@@ -39,16 +39,21 @@ function download_repo {
 
     # we need to download the repo code from GitHub in order to extract
     # the integration tests that were present in that version of the repo.
-    # TODO - consider switching this to 'npm install',
-    # apparently we publish the integ tests in the package.
-    version=$1
+    #
+    # Download just the CLI tarball, which contains the tests. We can't
+    # use 'npm pack' here to obtain the tarball, as 'npm' commands may
+    # be redirected to a local Verdaccio.
+    #
+    # Rather than introducing another level of indirection to work around
+    # that, just go to npmjs.com directly.
 
-    out="${temp_dir}/.repo.tar.gz"
+    # Strip off leading 'v'
+    version=${1#v}
 
-    curl -L -o ${out} "https://github.com/aws/aws-cdk/archive/${version}.tar.gz"
-    tar --strip-components=1 -zxf ${out} -C ${temp_dir}
-    echo ${temp_dir}
+    out="${temp_dir}/.repo.tar.gz"
 
+    curl -Ssf -L -o ${out} "https://registry.npmjs.org/aws-cdk/-/aws-cdk-${version}.tgz"
+    tar -zxf ${out} -C ${temp_dir}
 }
 
 # this allows injecting different versions to be treated as the baseline
@@ -59,7 +64,7 @@ VERSION_UNDER_TEST=${VERSION_UNDER_TEST:-$(get_latest_published_version)}
 trap cleanup INT EXIT
 
 echo "Downloading aws-cdk repo version ${VERSION_UNDER_TEST}"
-temp_repo_dir="$(download_repo ${VERSION_UNDER_TEST})"
+download_repo ${VERSION_UNDER_TEST}
 
 # remove '/' that is prevelant in our branch names but causes
 # bad behvaior when using it as directory names.
@@ -68,7 +73,11 @@ sanitized_version=$(sed 's/\//-/g' <<< "${VERSION_UNDER_TEST}")
 integ_under_test=${integdir}/cli-backwards-tests-${sanitized_version}
 rm -rf ${integ_under_test}
 echo "Copying integration tests of version ${VERSION_UNDER_TEST} to ${integ_under_test} (dont worry, its gitignored)"
-cp -r ${temp_dir}/packages/aws-cdk/test/integ/cli ${integ_under_test}
+cp -r ${temp_dir}/package/test/integ/cli ${integ_under_test}
+
+echo "Hotpatching the test runner (can be removed after release 1.40.0)" >&2
+cp -r ${integdir}/cli/test-jest.sh ${integ_under_test}
+cp -r ${integdir}/cli/jest.config.js ${integ_under_test}
 
 echo "Running integration tests of version ${VERSION_UNDER_TEST} from ${integ_under_test}"
 VERSION_UNDER_TEST=${VERSION_UNDER_TEST} ${integ_under_test}/test.sh