fix: forgot sourceLineForShell

lib/installer.js

@@ -57,10 +57,9 @@ const locationFromShell = shell => {
  * If the provided SHELL is not known, it returns the source line for a Bash shell.
  *
  * @param {String} scriptname - The script to source
- * @param {String} shell - Shell to base the check on, defaults to system
- * shell.
+ * @param {SupportedShell} shell - Shell to base the check on
  */
-const sourceLineForShell = (scriptname, shell = systemShell()) => {
+const sourceLineForShell = (scriptname, shell) => {
   if (shell === 'fish') {
     return `[ -f ${scriptname} ]; and . ${scriptname}; or true`;
   }
@@ -73,8 +72,11 @@ const sourceLineForShell = (scriptname, shell = systemShell()) => {
     return `if (Test-Path ${scriptname}) { . ${scriptname} }`;
   }
 
-  // For Bash and others
-  return `[ -f ${scriptname} ] && . ${scriptname} || true`;
+  if (shell === 'bash') {
+    return `[ -f ${scriptname} ] && . ${scriptname} || true`;
+  }
+
+  throw new Error(`Unsupported shell: ${shell}`);
 };
 
 /**
@@ -131,7 +133,7 @@ const checkFilenameForLine = async (filename, line) => {
  * @param {String} options.filename - The file to modify.
  * @param {String} options.scriptname - The line to add sourcing this file.
  * @param {String} options.name - The package being configured.
- * @param {String} options.shell
+ * @param {SupportedShell} options.shell
  * @returns {Promise.<void>}
  */
 const writeLineToFilename = ({ filename, scriptname, name, shell }) => new Promise((