Add template field to Link because ostatus subscribe schema needs it.

Also fixes a bug where Resource::compress lost every link and adds a lot more tests around that functionality.

src/schema/resource.rs

@@ -114,6 +114,7 @@ impl Resource {
                                         .map(clone_hashmap_with_option_value_as_complete)
                                         .unwrap_or_default(),
                                 ),
+                                template: Some(link.template.clone().unwrap_or_default()),
                             }
                         }))
                     })
@@ -146,6 +147,36 @@ impl Resource {
                 .links
                 .filter(|links| !links.is_empty())
                 .map(|mut links| {
+                    // Collapse default subvalues
+                    for link in &mut links {
+                        if link.media_type.as_ref().map_or(false, String::is_empty) {
+                            link.media_type = None;
+                        }
+                        if link.href.as_ref().map_or(false, String::is_empty) {
+                            link.href = None;
+                        }
+                        if let Some(titles) = &mut link.titles {
+                            titles.retain(|key, value| !key.is_empty() || !value.is_empty())
+                        }
+                        if link.titles.as_ref().map_or(false, HashMap::is_empty) {
+                            link.titles = None;
+                        }
+                        if let Some(properties) = &mut link.properties {
+                            for value in properties.values_mut() {
+                                if value.as_ref().map_or(false, String::is_empty) {
+                                    *value = None;
+                                }
+                            }
+                            properties.retain(|key, value| !key.is_empty() || !value.is_none())
+                        }
+                        if link.properties.as_ref().map_or(false, HashMap::is_empty) {
+                            link.properties = None;
+                        }
+                        if link.template.as_ref().map_or(false, String::is_empty) {
+                            link.template = None;
+                        }
+                    }
+                    // Delete completely default links
                     links.retain(|link| {
                         // Empty `rel` is invalid, but short-circuiting here would delete records
                         // that are only partially edited. Better to store invalid data than to delete
@@ -153,22 +184,19 @@ impl Resource {
                         let mut is_default = link.rel.is_empty();
                         is_default &= link
                             .media_type
-                            .as_ref()
-                            .filter(|media_type| !media_type.is_empty())
                             .is_none();
                         is_default &= link.href.as_ref().filter(|href| !href.is_empty()).is_none();
                         is_default &= link
                             .titles
-                            .as_ref()
-                            .filter(|titles| !titles.is_empty())
                             .is_none();
                         is_default &= link
                             .properties
-                            .as_ref()
+                            .is_none();
-                            .filter(|titles| !titles.is_empty())
+                        is_default &= link
+                            .template
                             .is_none();
 
-                        is_default
+                        !is_default
                     });
 
                     links
@@ -189,12 +217,15 @@ pub struct Link {
     pub titles: Option<HashMap<String, String>>,
     #[serde(skip_serializing_if = "Option::is_none")]
     pub properties: Option<HashMap<String, Option<String>>>,
+    #[serde(skip_serializing_if = "Option::is_none")]
+    pub template: Option<String>,
 }
 
 #[cfg(test)]
 /// Functions to generate data for testing functions that manipulate `Resource` structs
 pub mod test_data {
-    use crate::schema::resource::Resource;
+    use std::collections::HashMap;
+    use crate::schema::resource::{Link, Resource};
 
     /// A [`Resource`] with only the `subject` field set
     pub fn barebones_user() -> Resource {
@@ -220,6 +251,100 @@ pub mod test_data {
             links: None,
         }
     }
+
+    pub fn example_mastodon_user() -> Resource {
+        Resource {
+            subject: "acct:user@example.com".to_string(),
+            aliases: Some(vec![
+                "https://example.com/@user".to_string(),
+                "https://example.com/users/user".to_string()
+            ]),
+            properties: None,
+            links: Some(vec![
+                Link {
+                    rel: "http://webfinger.net/rel/profile-page".to_string(),
+                    media_type: Some("text/html".to_string()),
+                    href: Some("https://example.com/@user".to_string()),
+                    titles: None,
+                    properties: None,
+                    template: None,
+                },
+                Link {
+                    rel: "self".to_string(),
+                    media_type: Some("application/activity+json".to_string()),
+                    href: Some("https://example.com/users/user".to_string()),
+                    titles: None,
+                    properties: None,
+                    template: None,
+                },
+                Link {
+                    rel: "http://ostatus.org/schema/1.0/subscribe".to_string(),
+                    media_type: None,
+                    href: None,
+                    titles: None,
+                    properties: None,
+                    template: Some("https://example.com/authorize_interaction?uri={uri}".to_string()),
+                },
+                Link {
+                    rel: "http://webfinger.net/rel/avatar".to_string(),
+                    media_type: Some("image/png".to_string()),
+                    href: Some("https://example.com/system/accounts/avatars/321/423/112/234/123/527/original/1j2ioff88a9wa.png".to_string()),
+                    titles: None,
+                    properties: None,
+                    template: None,
+                }
+            ]),
+        }
+    }
+
+    pub fn example_firefish_user() -> Resource {
+        Resource {
+            subject: "acct:user@example.com".to_string(),
+            aliases: None,
+            properties: None,
+            links: Some(vec![
+                Link {
+                    rel: "self".to_string(),
+                    media_type: Some("application/activity+json".to_string()),
+                    href: Some("https://example.com/users/8fsua89lcieaj".to_string()),
+                    titles: None,
+                    properties: None,
+                    template: None,
+                },
+                Link {
+                    rel: "http://webfinger.net/rel/profile-page".to_string(),
+                    media_type: Some("text/html".to_string()),
+                    href: Some("https://example.com/@user".to_string()),
+                    titles: None,
+                    properties: None,
+                    template: None,
+                },
+                Link {
+                    rel: "http://ostatus.org/schema/1.0/subscribe".to_string(),
+                    media_type: None,
+                    href: None,
+                    titles: None,
+                    properties: None,
+                    template: Some("https://example.com/authorize-follow?acct={uri}".to_string()),
+                }
+            ])
+        }
+    }
+    pub fn full_resource() -> Resource {
+        Resource {
+            subject: "some_subject".to_string(),
+            aliases: Some(vec!["ThisIsAnAlias".to_string()]),
+            properties: Some(HashMap::from_iter(std::iter::once(("property_key".to_string(), Some("property_value".to_string()))))),
+            links: Some(vec![Link {
+                rel: "link_relation".to_string(),
+                media_type: Some("media/type".to_string()),
+                href: Some("https://example.com/link_href".to_string()),
+                titles: Some(HashMap::from_iter(std::iter::once(("title_key".to_string(), "title_value".to_string())))),
+                properties: Some(HashMap::from_iter(std::iter::once(("property_key".to_string(), Some("property_value".to_string()))))),
+                template: Some("template".to_string()),
+            }]),
+        }
+    }
 }
 
 #[cfg(test)]
@@ -288,6 +413,9 @@ mod tests {
             test_data::barebones_user(),
             test_data::user_with_matching_subject_and_alias(),
             test_data::user_with_single_alias(),
+            test_data::example_firefish_user(),
+            test_data::example_mastodon_user(),
+            test_data::full_resource(),
         ] {
             assert_eq!(data, data.as_completely_serializable().compress());
         }