From ae90cba34179ed890ddea07685c86e8be6e52e96 Mon Sep 17 00:00:00 2001
From: Niranjan Jayakar <nija@amazon.com>
Date: Tue, 9 Jun 2020 05:44:05 +0100
Subject: [PATCH] chore: re-enable using current pkg versions for api compat
 checks (#8427)

This was originally added in commit
https://github.com/aws/aws-cdk/commit/3dd21b9b212f96720519ac12f9cb538c697e9343.

However, the script fails during a bump build when the package version
in lerna.json is ahead of the latest published in NPM. This was worked
around by turning this feature off -
https://github.com/aws/aws-cdk/commit/09a1f33f975e49f92bfa708e3d3d03984863a28d.

Re-enable this feature and handle version in lerna.json may be ahead of
NPM.

### Testing

Manually tested three cases -
* When version in `lerna.json` is <= package published in NPM
* When version in `lerna.json` is > package published in NPM
* When `DOWNLOAD_LATEST` is set to `true`.

----

*By submitting this pull request, I confirm that my contribution is made under the terms of the Apache-2.0 license*
---
 build.sh                           |  2 +-
 scripts/check-api-compatibility.sh | 11 ++++++++---
 2 files changed, 9 insertions(+), 4 deletions(-)

diff --git a/build.sh b/build.sh
index 44c020454216a..b58fa80e1c563 100755
--- a/build.sh
+++ b/build.sh
@@ -60,6 +60,6 @@ echo "==========================================================================
 echo "building..."
 time lerna run $bail --stream $runtarget || fail
 
-DOWNLOAD_LATEST=true /bin/bash scripts/check-api-compatibility.sh
+/bin/bash scripts/check-api-compatibility.sh
 
 touch $BUILD_INDICATOR
diff --git a/scripts/check-api-compatibility.sh b/scripts/check-api-compatibility.sh
index a63ccb5f7fa9b..ca15553418f72 100755
--- a/scripts/check-api-compatibility.sh
+++ b/scripts/check-api-compatibility.sh
@@ -13,7 +13,9 @@ package_name() {
 #
 # Doesn't use 'npm view' as that is slow. Direct curl'ing npmjs is better
 package_exists_on_npm() {
-    curl -I 2>/dev/null https://registry.npmjs.org/$1 | head -n 1 | grep 200 >/dev/null
+    pkg=$1
+    ver=$2 # optional
+    curl -I 2>/dev/null https://registry.npmjs.org/$pkg/$ver | head -n 1 | grep 200 >/dev/null
 }
 
 
@@ -53,10 +55,13 @@ if ! ${SKIP_DOWNLOAD:-false}; then
     existing_names=$(echo "$jsii_package_dirs" | xargs -n1 -P4 -I {} bash -c 'dirs_to_existing_names "$@"' _ {})
     echo " Done." >&2
 
-    if ! ${DOWNLOAD_LATEST:-false}; then
-        current_version=$(node -p 'require("./lerna.json").version')
+    current_version=$(node -p 'require("./lerna.json").version')
+    echo "Current version in lerna.json is $current_version"
+    if ! ${DOWNLOAD_LATEST:-false} && package_exists_on_npm aws-cdk $current_version; then
         echo "Using package version ${current_version} as baseline"
         existing_names=$(echo "$existing_names" | sed -e "s/$/@$current_version/")
+    else
+        echo "However, using the latest version from NPM as the baseline"
     fi
 
     rm -rf $tmpdir