fix: compile handlebars multiple times to catch nested templates

Closes #1652

lib/workers/repository/updates/branchify.js

@@ -36,6 +36,9 @@ function branchifyUpgrades(config) {
         logger.debug('Using regular branchName template');
         upgrade.branchName = handlebars.compile(upgrade.branchName)(upgrade);
       }
+      // Compile extra times in case of nested handlebars templates
+      upgrade.branchName = handlebars.compile(upgrade.branchName)(upgrade);
+      upgrade.branchName = handlebars.compile(upgrade.branchName)(upgrade);
       branchUpgrades[upgrade.branchName] =
         branchUpgrades[upgrade.branchName] || [];
       branchUpgrades[upgrade.branchName] = [upgrade].concat(

lib/workers/repository/updates/generate.js

@@ -49,6 +49,9 @@ function generateBranchConfig(branchUpgrades) {
       upgrade.baseBranches && upgrade.baseBranches.length > 1
         ? ' ({{baseBranch}})'
         : '';
+    // Compile a few times to allow for nested handlebars templates
+    upgrade.prTitle = handlebars.compile(upgrade.prTitle)(upgrade);
+    upgrade.prTitle = handlebars.compile(upgrade.prTitle)(upgrade);
     upgrade.prTitle = handlebars.compile(upgrade.prTitle)(upgrade);
     if (upgrade.semanticCommits) {
       logger.debug('Upgrade has semantic commits enabled');