do nothing if nothing is pushed

Fixes: https://code.forgejo.org/actions/cascading-pr/issues/6

README.md

@@ -151,19 +151,8 @@ displayed if an error happens.
 ## snippets for copy/pasting
 
 ```sh
-git clone https://code.forgejo.org/actions/setup-forgejo
-export PATH=$(pwd)/setup-forgejo:$PATH
-git clone https://code.forgejo.org/actions/cascading-pr
-cd cascading-pr
-forgejo-curl.sh logout
-forgejo-runner.sh teardown
-forgejo.sh teardown
-forgejo.sh setup root admin1234 codeberg.org/forgejo/forgejo 1.21
-FORGEJO_RUNNER_CONFIG=$(pwd)/tests/runner-config.yaml forgejo-runner.sh setup
-url=http://$(cat forgejo-ip):3000
-firefox $url
 tests/run.sh --debug
-tests/run.sh --debug create_pull_request
+tests/run.sh --debug no_change_no_cascade_pr
 ./cascading-pr.sh --debug --origin-url "$url" --origin-repo "user1/originrepo" --origin-token "$(cat /tmp/cascading-pr-test/user1/repo-token)" --origin-pr 1 --destination-url "$url" --destination-repo "user2/destinationrepo" --destination-token "$(cat /tmp/cascading-pr-test/user2/repo-token)" --destination-branch "main" --update "upgraded" run
 ```
 

cascading-pr.sh

@@ -43,7 +43,7 @@ function delete_branch() {
 }
 
 function pr_origin_comment_body() {
-    echo "cascading-pr created at ${options[destination_url]}/${options[destination_repo]}/pulls/$(pr_number destination)"
+    echo "cascading-pr updated at ${options[destination_url]}/${options[destination_repo]}/pulls/$(pr_number destination)"
 }
 
 function comment_origin_pr() {
@@ -121,31 +121,39 @@ function pr_get_destination() {
     repo_curl ${options[destination_repo]} api --get --data state=open --data type=pulls --data-urlencode q="$title" ${options[destination_api]}/issues | jq --raw-output .[0]  > $TMPDIR/destination-pr.json
 }
 
-function pr() {
+function pr_get() {
     local direction=$1
     if ! test -f $TMPDIR/${direction}-pr.json; then
 	pr_get_$direction
     fi
-    cat $TMPDIR/${direction}-pr.json
+}
+
+function pr()  {
+    cat $TMPDIR/$1-pr.json
 }
 
 function pr_state() {
+    pr_get $1
     pr $1 | jq --raw-output .state
 }
 
 function pr_url() {
+    pr_get $1
     pr $1 | jq --raw-output .url
 }
 
 function pr_number() {
+    pr_get $1
     pr $1 | jq --raw-output .number
 }
 
 function pr_head() {
+    pr_get $1
     pr $1 | jq --raw-output .head.ref
 }
 
 function pr_merged() {
+    pr_get $1
     pr $1 | jq --raw-output .merged
 }
 
@@ -168,6 +176,13 @@ function upsert_clone() {
     )
 }
 
+function sha_pushed() {
+    local direction=$1
+    if test -f $TMPDIR/$direction.sha ; then
+	cat $TMPDIR/$direction.sha
+    fi
+}
+
 function push() {
     local direction=$1 branch=$2 clone=$3
 
@@ -176,11 +191,11 @@ function push() {
 	git add .
 	if git commit -m 'cascading-pr update'; then
 	    git push --force origin $branch
+	    git rev-parse HEAD > ../$direction.sha
 	    log_info "pushed"
 	else
 	    log_info "nothing to push"
 	fi
-	git rev-parse HEAD > ../$direction.sha
     )
 }
 
@@ -240,18 +255,21 @@ function run() {
 	    log_info "PR is open, update or create the cascade branch and PR"
 	    repo_login ${options[destination_repo]}
 	    upsert_destination_branch
-	    upsert_destination_pr
-	    repo_login ${options[origin_repo]}
-	    comment_origin_pr
 	    update
-	    wait_destination_ci $(cat $TMPDIR/destination.sha)
+	    local sha=$(sha_pushed destination)
+	    if test "$sha" ; then
+		upsert_destination_pr
+		repo_login ${options[origin_repo]}
+		comment_origin_pr
+		wait_destination_ci "$sha"
+	    fi
 	    ;;
 	closed)
 	    if "$(pr_merged origin)"; then
 		log_info "PR was merged, update the cascade PR"
 		repo_login ${options[destination_repo]}
-		pr origin
+		pr_get origin
-		pr destination
+		pr_get destination
 		update
 	    else
 		log_info "PR is closed, close the cascade PR and remove the branch"

tests/originrepo-do-nothing/.forgejo/workflows/test.yml

@@ -0,0 +1,25 @@
+# SPDX-License-Identifier: MIT
+name: test
+on:
+  pull_request:
+    types:
+      - opened
+      - synchronize
+      - closed
+jobs:
+  test:
+    runs-on: docker
+    steps:
+      - uses: actions/checkout@v4
+      - uses: SELF@vTest
+        with:
+          origin-url: ${{ env.GITHUB_SERVER_URL }}
+          origin-repo: user1/originrepo-do-nothing
+          origin-token: ${{ secrets.ORIGIN_TOKEN }}
+          origin-pr: ${{ github.event.pull_request.number }}
+          destination-url: ${{ env.GITHUB_SERVER_URL }}
+          destination-repo: user2/destinationrepo
+          destination-branch: main
+          destination-token: ${{ secrets.DESTINATION_TOKEN }}
+          update: /bin/true
+          debug: true

tests/originrepo-do-nothing/README

@@ -0,0 +1 @@
+originrepo

tests/originrepo/upgraded

@@ -7,7 +7,6 @@ destination_pr_json="$2"
 origin_pr_json="$3"
 
 test -d $destination_checkout
-test -f $destination_pr_json
 test -f $origin_pr_json
 
 date +%s > $destination_checkout/last

tests/run.sh

@@ -38,7 +38,7 @@ function user_token() {
 function user_secret() {
     local username=$1 name=$2 token=$3
 
-    user_curl $username api_json -X PUT --data '{"data":"'$token'"}' ${options[url]}/api/v1/repos/user1/originrepo/actions/secrets/$name
+    user_curl $username api_json -X PUT --data '{"data":"'$token'"}' ${options[url]}/api/v1/user/actions/secrets/$name
 }
 
 function user_create() {
@@ -60,27 +60,34 @@ function merge_pull_request() {
     done
 }
 
+function has_cascade_pull_request() {
+    pr_count=$(forgejo-curl.sh api_json ${options[url]}/api/v1/repos/user2/destinationrepo/pulls | jq '. | length')
+    test $pr_count -gt 0
+}
+
 function create_pull_request() {
-    forgejo-curl.sh api_json ${options[url]}/api/v1/repos/user1/originrepo/pulls | jq --raw-output '.[] | .number' | while read pr ; do
+    local originrepo=$1
-	forgejo-curl.sh api_json -X DELETE ${options[url]}/api/v1/repos/user1/originrepo/issues/$pr
+
+    forgejo-curl.sh api_json ${options[url]}/api/v1/repos/user1/${originrepo}/pulls | jq --raw-output '.[] | .number' | while read pr ; do
+	forgejo-curl.sh api_json -X DELETE ${options[url]}/api/v1/repos/user1/${originrepo}/issues/$pr
     done
-    forgejo-curl.sh api_json -X DELETE ${options[url]}/api/v1/repos/user1/originrepo/branches/branch1 >& /dev/null || true
+    forgejo-curl.sh api_json -X DELETE ${options[url]}/api/v1/repos/user1/${originrepo}/branches/branch1 >& /dev/null || true
-    forgejo-curl.sh api_json --data '{"new_branch_name":"branch1"}' ${options[url]}/api/v1/repos/user1/originrepo/branches
+    forgejo-curl.sh api_json --data '{"new_branch_name":"branch1"}' ${options[url]}/api/v1/repos/user1/${originrepo}/branches
     (
 	cd $TMPDIR
-	rm -fr originrepo
+	rm -fr ${originrepo}
-	git clone -b branch1 http://user1:admin1234@${options[host_port]}/user1/originrepo
+	git clone -b branch1 http://user1:admin1234@${options[host_port]}/user1/${originrepo}
-	cd originrepo
+	cd ${originrepo}
 	echo CONTENT > README
 	git config user.email root@example.com
 	git config user.name username
 	git add .
 	git commit -m 'update'
 	git push origin branch1
-	git rev-parse HEAD > ../originrepo.sha
+	git rev-parse HEAD > ../${originrepo}.sha
     )
 
-    forgejo-curl.sh api_json --data '{"title":"PR","base":"main","head":"branch1"}' ${options[url]}/api/v1/repos/user1/originrepo/pulls
+    forgejo-curl.sh api_json --data '{"title":"PR","base":"main","head":"branch1"}' ${options[url]}/api/v1/repos/user1/${originrepo}/pulls
 }
 
 function finalize_options() {
@@ -143,34 +150,55 @@ function unit_retry() {
     grep --quiet 'retry failed' $TMPDIR/retry.log
 }
 
-function integration() {
+function fixture() {
+    local origin=$1
+    local destination=$2
+
     user_create user2 user2@example.com
-    forgejo-test-helper.sh push tests/destinationrepo http://user2:admin1234@${options[host_port]} user2 destinationrepo
+    forgejo-test-helper.sh push tests/${destination} http://user2:admin1234@${options[host_port]} user2 ${destination}
 
     user_create user1 user1@example.com
-    forgejo-test-helper.sh push tests/originrepo http://user1:admin1234@${options[host_port]} user1 originrepo cascading-pr
+    forgejo-test-helper.sh push tests/${origin} http://user1:admin1234@${options[host_port]} user1 ${origin} cascading-pr
     user_secret user1 ORIGIN_TOKEN $(user_token user1 ORIGIN_TOKEN)
     user_secret user1 DESTINATION_TOKEN $(user_token user2 DESTINATION_TOKEN)
 
     push_self
+}
 
-    #
+function no_change_no_cascade_pr() {
-    # create & close
+    fixture originrepo-do-nothing destinationrepo
-    #
+
-    create_pull_request
+    create_pull_request originrepo-do-nothing
+    wait_success ${options[url]}/api/v1/repos/user1/originrepo-do-nothing $(cat $TMPDIR/originrepo-do-nothing.sha)
+    ! has_cascade_pull_request
+}
+
+function create_and_close() {
+    fixture originrepo destinationrepo
+
+    create_pull_request originrepo
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
+    has_cascade_pull_request
     close_pull_request
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
+}
 
-    #
+function create_and_merge() {
-    # create & merge
+    fixture originrepo destinationrepo
-    #
+
-    create_pull_request
+    create_pull_request originrepo
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
+    has_cascade_pull_request
     merge_pull_request
     wait_success ${options[url]}/api/v1/repos/user1/originrepo $(cat $TMPDIR/originrepo.sha)
 }
 
+function integration() {
+    no_change_no_cascade_pr
+    create_and_close
+    create_and_merge
+}
+
 function unit() {
     unit_retry
 }