test(nodejs): Port nodejs module tests from E2E to integraton (#867)

Replaces the existing nodejs module end-to-end tests with integration tests that don't require preinstalled environmental dependencies.

- Moved the tests to the same file as the module they test
- Created a render_module utility function for rendering modules within tests
- Removed Node.js installation during CI setup
- Add Shell to Context to allow for tests to not run shell-specific code

1 files changed, 3 insertions, 4 deletions

diff --git a/src/modules/battery.rs b/src/modules/battery.rs
index 8c651a954..55e248e57 100644
--- a/src/modules/battery.rs
+++ b/src/modules/battery.rs
@@ -1,13 +1,12 @@
-use super::{Context, Module, RootModuleConfig};
+use super::{Context, Module, RootModuleConfig, Shell};
 use crate::configs::battery::BatteryConfig;
 
 /// Creates a module for the battery percentage and charging state
 pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
     // TODO: Update when v1.0 printing refactor is implemented to only
     // print escapes in a prompt context.
-    let shell = std::env::var("STARSHIP_SHELL").unwrap_or_default();
-    let percentage_char = match shell.as_str() {
-        "zsh" => "%%", // % is an escape in zsh, see PROMPT in `man zshmisc`
+    let percentage_char = match context.shell {
+        Shell::Zsh => "%%", // % is an escape in zsh, see PROMPT in `man zshmisc`
         _ => "%",
     };