Modify CI to allow for main default branch

Goal is to make CI scripts work with a default branch of main or
master.

notes:

`git symbolic-ref refs/remotes/origin/HEAD` worked locally but not
on GitHub actions.

references:

- actions/checkout#283 (comment)
- https://github.com/thoughtbot/dotfiles/blob/2a59c1890f81bffc1db79cae4482ce2b706b0f79/bin/git-up
- https://github.com/actions/checkout/pull/284/files
- jhauberg/gitdoctor#3 (comment)

.appveyor.yml

@@ -8,10 +8,11 @@ skip_branch_with_pr: true
 # to only build commits from pull requests
 branches:
   only:
+    - main
     - master
 
 # Only run AppVeyor on commits that modify at least one of the following files
-# Delete these lines to run AppVeyor on all master branch commits
+# Delete these lines to run AppVeyor on all main/master branch commits
 only_commits:
   files:
     - .appveyor.yml

.github/workflows/manubot.yaml

@@ -2,9 +2,11 @@ name: Manubot
 on:
   push:
     branches:
+      - main
       - master
   pull_request:
     branches:
+      - main
       - master
 jobs:
   manubot:
@@ -14,23 +16,27 @@ jobs:
       GITHUB_PULL_REQUEST_SHA: ${{ github.event.pull_request.head.sha }}
       SPELLCHECK: true
     steps:
-      - name: Set Environment Variables
-        run: |
-          TRIGGERING_SHA=${GITHUB_PULL_REQUEST_SHA:-$GITHUB_SHA}
-          echo "TRIGGERING_SHA_7=${TRIGGERING_SHA::7}" >> $GITHUB_ENV
-          echo "TRIGGERING_SHA: $TRIGGERING_SHA"
       - name: Checkout Repository
         uses: actions/checkout@v2
         with:
           # fetch entire commit history to support get_rootstock_commit
           fetch-depth: 0
+      - name: Set Environment Variables
+        run: |
+          TRIGGERING_SHA=${GITHUB_PULL_REQUEST_SHA:-$GITHUB_SHA}
+          echo "TRIGGERING_SHA_7=${TRIGGERING_SHA::7}" >> $GITHUB_ENV
+          echo "TRIGGERING_SHA: $TRIGGERING_SHA"
+          DEFAULT_BRANCH=$(git remote show origin | grep --perl-regexp --only-matching "(?<=HEAD branch: ).+")
+          echo "DEFAULT_BRANCH=${DEFAULT_BRANCH}" >> $GITHUB_ENV
+          echo "DEFAULT_BRANCH_REF=refs/heads/$DEFAULT_BRANCH" >> $GITHUB_ENV
+          echo "DEFAULT_BRANCH=$DEFAULT_BRANCH"
       - name: Cache
         uses: actions/cache@v1
         with:
           path: ci/cache
           key: ci-cache-${{ github.ref }}
           restore-keys: |
-            ci-cache-refs/heads/master
+            ci-cache-${{ env.DEFAULT_BRANCH_REF }}
       - name: Install Environment
         uses: conda-incubator/setup-miniconda@v2
         with:
@@ -53,7 +59,7 @@ jobs:
           name: manuscript-${{ github.run_id }}-${{ env.TRIGGERING_SHA_7 }}
           path: output
       - name: Deploy Manuscript
-        if: github.ref == 'refs/heads/master' && github.event_name == 'push' && !github.event.repository.fork
+        if: github.ref == env.DEFAULT_BRANCH_REF && github.event_name == 'push' && !github.event.repository.fork
         env:
           MANUBOT_ACCESS_TOKEN: ${{ secrets.GITHUB_TOKEN }}
           MANUBOT_SSH_PRIVATE_KEY: ${{ secrets.MANUBOT_SSH_PRIVATE_KEY }}

.travis.yml

@@ -5,6 +5,7 @@ services:
   - docker
 branches:
   only:
+    - main
     - master
 env:
   - SPELLCHECK=true
@@ -20,5 +21,6 @@ deploy:
   script: bash ci/deploy.sh
   skip_cleanup: true
   on:
+    # branch kept as master since travis deployment is legacy.
     branch: master
     condition: $TRAVIS_EVENT_TYPE = "push" && (-v MANUBOT_SSH_PRIVATE_KEY || "${!encrypted_*}" != "")

ci/deploy.sh

@@ -12,7 +12,8 @@ REPO_SLUG=${TRAVIS_REPO_SLUG:-$GITHUB_REPOSITORY}
 COMMIT=${TRAVIS_COMMIT:-$GITHUB_SHA}
 CI_BUILD_WEB_URL=${CI_BUILD_WEB_URL:-$TRAVIS_BUILD_WEB_URL}
 CI_JOB_WEB_URL=${CI_JOB_WEB_URL:-$TRAVIS_JOB_WEB_URL}
-BRANCH=${TRAVIS_BRANCH:-master}
+BRANCH=${TRAVIS_BRANCH:-$DEFAULT_BRANCH}
+BRANCH=${BRANCH:-$main}
 
 # Add commit hash to the README
 OWNER_NAME="$(dirname "$REPO_SLUG")"