Fix non-preview draft PR builds

.circleci/config.yml

@@ -350,27 +350,9 @@ jobs:
             # required and add the new dependencies, and the cache will be persisted.
             - dependency-cache-v1-
       - gh/install
-      - run:
-          name: Set IS_DRAFT environment variable
-          command: |
-            PR_NUMBER="${CIRCLE_PULL_REQUEST##*/}"
-            if [ -n "$PR_NUMBER" ]
-            then
-              echo "IS_DRAFT=$(gh pr view --json isDraft --jq '.isDraft' "$PR_NUMBER")" >> "$BASH_ENV"
-              source "$BASH_ENV"
-            else
-              echo "Not a PR; skipping"
-            fi
       - run:
           name: Install dependencies
-          command: |
-            if [[ $IS_DRAFT == 'true' ]]
-            then
-              # Use GitHub registry on draft PRs, allowing the use of preview builds
-              METAMASK_NPM_REGISTRY=https://npm.pkg.github.com yarn --immutable
-            else
-              yarn --immutable
-            fi
+          command: .circleci/scripts/install-dependencies.sh
       - save_cache:
           key: dependency-cache-v1-{{ checksum "yarn.lock" }}
           paths:

.circleci/scripts/install-dependencies.sh

@@ -0,0 +1,40 @@
+#!/usr/bin/env bash
+
+set -e
+set -u
+set -o pipefail
+
+PR_NUMBER="${CIRCLE_PULL_REQUEST##*/}"
+if [ -n "$PR_NUMBER" ]
+then
+  IS_DRAFT="$(gh pr view --json isDraft --jq '.isDraft' "$PR_NUMBER")"
+else
+  IS_DRAFT='false'
+fi
+
+# Build query to see whether there are any "preview-like" packages in the manifest
+# A "preview-like" package is a `@metamask`-scoped package with a prerelease version that has no period.
+QUERY='.dependencies + .devDependencies'                            # Get list of all dependencies
+QUERY+=' | with_entries( select(.key | startswith("@metamask") ) )' # filter to @metamask-scoped packages
+QUERY+=' | to_entries[].value'                                      # Get version ranges
+QUERY+=' | select(test("^\\d+\\.\\d+\\.\\d+-[^.]+$"))'              # Get pinned versions where the prerelease part has no "."
+
+# Use `-e` flag so that exit code indicates whether any matches were found
+if jq -e "${QUERY}" < ./package.json
+then
+  echo "Preview builds detected"
+  HAS_PREVIEW_BUILDS='true'
+else
+  echo "No preview builds detected"
+  HAS_PREVIEW_BUILDS='false'
+fi
+
+if [[ $IS_DRAFT == 'true' && $HAS_PREVIEW_BUILDS == 'true' ]]
+then
+  # Use GitHub registry on draft PRs, allowing the use of preview builds
+  echo "Installing with preview builds"
+  METAMASK_NPM_REGISTRY=https://npm.pkg.github.com yarn --immutable
+else
+  echo "Installing without preview builds"
+  yarn --immutable
+fi