feat(nextjs): Add ability for integration tests to use linked @sentry/xxxx packages (#4019)

In the nextjs integration tests, we use file dependencies for all of the packages in the `sentry-javascript` repo, so that the tests test the local (rather than published) version of the SDK. We don't do the same for `@sentry/cli` or `@sentry/webpack-plugin`, though, because they're in a separate repo and we can't predict where the local copy of that repo lives. As a result, we currently can't (in the nextjs integration tests, at least) test any local changes in either package.

This solves that problem by optionally linking to the local copies of those repos as part of the integration test runner script. In order to use this optional linking:

- To link `@sentry/cli`, set `LINKED_CLI_REPO=<abs path of local sentry-cli repo>`.
- To link `@sentry/webpack-plugin`, set the CLI variable above (since `@sentry/cli` is a dependency of `@sentry/webpack-plugin`, we need to link it in the plugin repo also) as well as `LINKED_PLUGIN_REPO=<abs path of local sentry-webpack-plugin repo>`

Author: lobsterkatie

packages/nextjs/test/integration_test_utils.sh

@@ -0,0 +1,51 @@
+function link_package() {
+  local package_abs_path=$1
+  local package_name=$2
+
+  echo "Setting up @sentry/${package_name} for linking"
+  pushd $package_abs_path
+  yarn link
+  popd
+
+  echo "Linking @sentry/$package_name"
+  yarn link "@sentry/$package_name"
+
+}
+
+# Note: LINKED_CLI_REPO and LINKED_PLUGIN_REPO in the functions below should be set to the absolute path of each local repo
+
+function linkcli() {
+  if [[ ! $LINKED_CLI_REPO ]]; then
+    return
+  fi
+
+  # check to make sure the repo directory exists
+  if [[ -d $LINKED_CLI_REPO ]]; then
+    link_package $LINKED_CLI_REPO "cli"
+  else
+    # the $1 lets us insert a string in that spot if one is passed to `linkcli` (useful for when we're calling this from
+    # within another linking function)
+    echo "ERROR: Can't link @sentry/cli $1because directory $LINKED_CLI_REPO does not exist."
+  fi
+}
+
+function linkplugin() {
+  if [[ ! $LINKED_PLUGIN_REPO ]]; then
+    return
+  fi
+
+  # check to make sure the repo directory exists
+  if [[ -d $LINKED_PLUGIN_REPO ]]; then
+    link_package $LINKED_PLUGIN_REPO "webpack-plugin"
+
+    # the webpack plugin depends on `@sentry/cli`, so if we're also using a linked version of the cli package, the
+    # plugin needs to link to it, too
+    if [[ $LINKED_CLI_REPO ]]; then
+      pushd $LINKED_PLUGIN_REPO
+      link_cli "in webpack plugin repo "
+      popd
+    fi
+  else
+    echo "ERROR: Can't link @sentry/wepack-plugin because $LINKED_PLUGIN_REPO does not exist."
+  fi
+}

packages/nextjs/test/run-integration-tests.sh

@@ -1,5 +1,7 @@
 #!/usr/bin/env bash
 
+source test/integration_test_utils.sh
+
 set -e
 
 START_TIME=$(date -R)
@@ -55,6 +57,9 @@ for NEXTJS_VERSION in 10 11; do
     sed -i /"next.*latest"/s/latest/"${NEXTJS_VERSION}.x"/ package.json
   fi
   yarn --no-lockfile --silent >/dev/null 2>&1
+  # if applicable, use local versions of `@sentry/cli` and/or `@sentry/webpack-plugin` (these commands no-op unless
+  # LINKED_CLI_REPO and/or LINKED_PLUGIN_REPO is set)
+  linkcli && linkplugin
   mv -f package.json.bak package.json 2>/dev/null || true
 
   for RUN_WEBPACK_5 in false true; do
@@ -72,9 +77,10 @@ for NEXTJS_VERSION in 10 11; do
     echo "[nextjs@$NEXTJS_VERSION | webpack@$WEBPACK_VERSION] Building..."
     yarn build | grep "Using webpack"
 
+    # if the user hasn't passed any args, use the default one, which restricts each test to only outputting success and
+    # failure messages
     args=$*
     if [[ ! $args ]]; then
-      # restrict each test to only output success and failure messages
       args="--silent"
     fi