emails: Implement template inheritance system for consistent branding

Author: Turbo87

src/controllers/krate/snapshots/crates_io__controllers__krate__delete__tests__happy_path_new_crate-3.snap

@@ -8,11 +8,15 @@ Subject: crates.io: Successfully published foo@1.0.0
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 A new version of the package foo (1.0.0) was published by your account (https://crates.io/users/foo) at [0000-00-00T00:00:00Z].
 
 If you have questions or security concerns, you can contact us at help@crates.io. If you would like to stop receiving these security notifications, you can disable them in your account settings.
+
+--
+The crates.io Team
 ----------------------------------------
 
 To: foo@example.com
@@ -21,8 +25,12 @@ Subject: crates.io: Deleted "foo" crate
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hi foo,
 
 Your "foo" crate has been deleted, per your request.
 
 If you did not initiate this deletion, your account may have been compromised. Please contact us at help@crates.io.
+
+--
+The crates.io Team

src/controllers/krate/snapshots/crates_io__controllers__krate__delete__tests__happy_path_old_crate-3.snap

@@ -8,11 +8,15 @@ Subject: crates.io: Successfully published foo@1.0.0
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 A new version of the package foo (1.0.0) was published by your account (https://crates.io/users/foo) at [0000-00-00T00:00:00Z].
 
 If you have questions or security concerns, you can contact us at help@crates.io. If you would like to stop receiving these security notifications, you can disable them in your account settings.
+
+--
+The crates.io Team
 ----------------------------------------
 
 To: foo@example.com
@@ -21,8 +25,12 @@ Subject: crates.io: Deleted "foo" crate
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hi foo,
 
 Your "foo" crate has been deleted, per your request.
 
 If you did not initiate this deletion, your account may have been compromised. Please contact us at help@crates.io.
+
+--
+The crates.io Team

src/controllers/krate/snapshots/crates_io__controllers__krate__delete__tests__happy_path_really_old_crate-3.snap

@@ -8,11 +8,15 @@ Subject: crates.io: Successfully published foo@1.0.0
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 A new version of the package foo (1.0.0) was published by your account (https://crates.io/users/foo) at [0000-00-00T00:00:00Z].
 
 If you have questions or security concerns, you can contact us at help@crates.io. If you would like to stop receiving these security notifications, you can disable them in your account settings.
+
+--
+The crates.io Team
 ----------------------------------------
 
 To: foo@example.com
@@ -21,8 +25,12 @@ Subject: crates.io: Deleted "foo" crate
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hi foo,
 
 Your "foo" crate has been deleted, per your request.
 
 If you did not initiate this deletion, your account may have been compromised. Please contact us at help@crates.io.
+
+--
+The crates.io Team

src/controllers/trustpub/github_configs/create/snapshots/crates_io__controllers__trustpub__github_configs__create__tests__happy_path-3.snap

@@ -8,6 +8,7 @@ Subject: crates.io: Trusted Publishing configuration added to foo
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 crates.io user foo added a new "Trusted Publishing" configuration for GitHub Actions to a crate that you manage ("foo"). Trusted publishers act as trusted users and can publish new versions of the crate automatically.
@@ -22,3 +23,6 @@ Trusted Publishing configuration:
 If you did not make this change and you think it was made maliciously, you can remove the configuration from the crate via the "Settings" tab on the crate's page.
 
 If you are unable to revert the change and need to do so, you can email help@crates.io for assistance.
+
+--
+The crates.io Team

src/controllers/trustpub/github_configs/delete/snapshots/crates_io__controllers__trustpub__github_configs__delete__tests__happy_path-2.snap

@@ -8,6 +8,7 @@ Subject: crates.io: Trusted Publishing configuration removed from foo
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 crates.io user foo removed a "Trusted Publishing" configuration for GitHub Actions from a crate that you manage ("foo").
@@ -20,3 +21,6 @@ Trusted Publishing configuration:
 - Environment: (not set)
 
 If you did not make this change and you think it was made maliciously, you can email help@crates.io for assistance.
+
+--
+The crates.io Team

src/controllers/user/snapshots/crates_io__controllers__user__email_verification__tests__happy_path-3.snap

@@ -8,10 +8,14 @@ Subject: crates.io: Please confirm your email address
 Content-Type: text/plain; charset=utf-8
 Content-Transfer-Encoding: quoted-printable
 
+
 Hello foo!
 
 Welcome to crates.io. Please click the link below to verify your email address:
 
 https://crates.io/confirm/[confirm-token]
 
 Thank you!
+
+--
+The crates.io Team

src/email.rs

@@ -16,24 +16,40 @@ use std::sync::LazyLock;
 static EMAIL_ENV: LazyLock<Environment<'static>> = LazyLock::new(|| {
     let mut env = Environment::new();
 
-    // Load templates from each email directory
+    // Load templates from the templates directory
     let entries = std::fs::read_dir("src/email/templates");
     let entries = entries.expect("Failed to read email templates directory");
 
     for entry in entries {
         let entry = entry.expect("Failed to read directory entry");
 
+        let path = entry.path();
         let file_type = entry.file_type().expect("Failed to get file type");
+
+        // Handle base template files
+        if file_type.is_file() && path.extension().and_then(|s| s.to_str()) == Some("j2") {
+            let template_name = entry.file_name();
+            let template_name = template_name.to_str();
+            let template_name = template_name.expect("Invalid UTF-8 in template filename");
+
+            let template_contents = std::fs::read_to_string(&path)
+                .unwrap_or_else(|error| panic!("Failed to read template {template_name}: {error}"));
+
+            env.add_template_owned(template_name.to_string(), template_contents)
+                .expect("Failed to add template");
+        }
+
         if !file_type.is_dir() {
             continue;
         }
 
+        // Handle email template directories
         let dir_name = entry.file_name();
         let email_name = dir_name.to_str();
         let email_name = email_name.expect("Invalid UTF-8 in email template directory name");
 
         // Load subject.txt.j2 file
-        let subject_path = entry.path().join("subject.txt.j2");
+        let subject_path = path.join("subject.txt.j2");
         let subject_contents = std::fs::read_to_string(&subject_path).unwrap_or_else(|error| {
             panic!("Failed to read subject template for {email_name}: {error}")
         });
@@ -42,7 +58,7 @@ static EMAIL_ENV: LazyLock<Environment<'static>> = LazyLock::new(|| {
             .expect("Failed to add subject template");
 
         // Load body.txt.j2 file
-        let body_path = entry.path().join("body.txt.j2");
+        let body_path = path.join("body.txt.j2");
         let body_contents = std::fs::read_to_string(&body_path).unwrap_or_else(|error| {
             panic!("Failed to read body template for {email_name}: {error}")
         });
@@ -234,6 +250,35 @@ pub struct StoredEmail {
 mod tests {
     use super::*;
     use claims::{assert_err, assert_ok};
+    use minijinja::context;
+
+    #[test]
+    fn test_user_confirm_template_inheritance() {
+        // Test that the `user_confirm` template inherits properly from the base template
+        let result = render_template(
+            "user_confirm/body.txt.j2",
+            context! {
+                domain => "crates.io",
+                user_name => "testuser",
+                token => "abc123"
+            },
+        );
+        assert_ok!(&result);
+
+        let content = result.unwrap();
+        insta::assert_snapshot!(content, @r"
+        Hello testuser!
+
+        Welcome to crates.io. Please click the link below to verify your email address:
+
+        https://crates.io/confirm/abc123
+
+        Thank you!
+
+        --
+        The crates.io Team
+        ");
+    }
 
     #[tokio::test]
     async fn sending_to_invalid_email_fails() {

src/email/templates/admin_account/body.txt.j2

@@ -1,3 +1,6 @@
+{% extends "base.txt.j2" %}
+
+{% block content %}
 {% if added_admins -%}
 Granted admin access:
 
@@ -10,4 +13,5 @@ Revoked admin access:
 {% for admin in removed_admins -%}
 - {{ admin }}
 {% endfor -%}
-{% endif %}
+{% endif %}
+{% endblock %}

src/email/templates/base.txt.j2

@@ -0,0 +1,3 @@
+{% block content %}{% endblock %}
+--
+The crates.io Team

src/email/templates/config_created/body.txt.j2

@@ -1,3 +1,6 @@
+{% extends "base.txt.j2" %}
+
+{% block content %}
 Hello {{ recipient }}!
 
 crates.io user {{ user }} added a new "Trusted Publishing" configuration for GitHub Actions to a crate that you manage ("{{ krate }}"). Trusted publishers act as trusted users and can publish new versions of the crate automatically.
@@ -12,3 +15,4 @@ Trusted Publishing configuration:
 If you did not make this change and you think it was made maliciously, you can remove the configuration from the crate via the "Settings" tab on the crate's page.
 
 If you are unable to revert the change and need to do so, you can email help@crates.io for assistance.
+{% endblock %}