derive_builder pattern is applied successfully.

This is mostly an exercise to understand the derive_builder pattern.
It required a few tips to get it working, but in the end, it's
actually what I want.

I also learned a lot about how the Executor pattern, the Results<> object,
error mapping, and futures interact in this code.  This is going to be
incredibly useful long-term, as long as I still keep this project "live"
in my head.

server/nm-store/Cargo.toml

@@ -14,6 +14,9 @@ readme = "./README.org"
 friendly_id = "0.3.0"
 thiserror = "1.0.20"
 derive_builder = "0.9.0"
+lazy_static = "1.4.0"
+regex = "1.3.9"
+slug = "0.1.4"
 tokio = { version = "0.2.22", features = ["rt-threaded", "blocking"] }
 serde = { version = "1.0.116", features = ["derive"] }
 serde_json = "1.0.56"

server/nm-store/src/errors.rs

@@ -13,6 +13,6 @@ pub enum NoteStoreError {
     NotFound,
 
     /// All other errors from the database.
-    #[error(transparent)]
+    #[error("Sqlx")]
     DBError(#[from] sqlx::Error),
 }

server/nm-store/src/lib.rs

@@ -1,4 +1,3 @@
-use chrono::{DateTime, Utc};
 mod errors;
 mod row_structs;
 mod store;
@@ -9,6 +8,7 @@ pub use crate::store::NoteStore;
 
 #[cfg(test)]
 mod tests {
+	use chrono;
     use super::*;
     use tokio;
 
@@ -38,12 +38,12 @@ mod tests {
     #[tokio::test(threaded_scheduler)]
     async fn fetching_unfound_page_by_title_works() {
         let title = "Nonexistent Page";
-        let now = chrono::Utc::now();
+        let _now = chrono::Utc::now();
         let storagepool = fresh_inmemory_database().await;
         let newpageresult = storagepool.get_page_by_title(&title).await;
 
-        assert!(newpageresult.is_ok(), "{:?}", newpage);
+        assert!(newpageresult.is_ok(), "{:?}", newpageresult);
-        let (newpage, newnotes) = newpageresult.unwrap();
+        let (newpage, _newnotes) = newpageresult.unwrap();
 
         assert_eq!(newpage.title, title, "{:?}", newpage.title);
         assert_eq!(newpage.slug, "nonexistent-page");

server/nm-store/src/row_structs.rs

@@ -1,5 +1,5 @@
 use chrono::{DateTime, Utc};
-use derive_builder;
+use derive_builder::Builder;
 use serde::{Deserialize, Serialize};
 use sqlx::{self, FromRow};
 
@@ -32,12 +32,13 @@ pub struct NewPage {
     pub slug: String,
     pub title: String,
     pub note_id: i64,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub creation_date: DateTime<Utc>,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub updated_date: DateTime<Utc>,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub lastview_date: DateTime<Utc>,
+    #[builder(default = r#"None"#)]
     pub deleted_date: Option<DateTime<Utc>>,
 }
 
@@ -45,28 +46,43 @@ pub struct NewPage {
 pub struct NewNote {
     pub uuid: String,
     pub content: String,
-    #[builder(default = "note")]
+    #[builder(default = r#""note".to_string()"#)]
     pub notetype: String,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub creation_date: DateTime<Utc>,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub updated_date: DateTime<Utc>,
-    #[builder(default = "chrono::Utc::now()")]
+    #[builder(default = r#"chrono::Utc::now()"#)]
     pub lastview_date: DateTime<Utc>,
+    #[builder(default = r#"None"#)]
     pub deleted_date: Option<DateTime<Utc>>,
 }
 
+#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
+pub(crate) struct JustSlugs {
+    pub slug: String,
+}
+
+#[derive(Clone, Serialize, Deserialize, Debug, FromRow)]
+pub struct JustTitles {
+    title: String,
+}
+
 #[cfg(test)]
 mod tests {
     use super::*;
 
     #[test]
-    fn can_build_new_page() {
+    fn can_build_new_note() {
         let now = chrono::Utc::now();
-        let newnote = NewNoteBuilder::default();
+        let newnote = NewNoteBuilder::default()
-        assert!((newnote.creation_date - now).num_minutes() < 1.0);
+            .uuid("foo".to_string())
-        assert!((newnote.updated_date - now).num_minutes() < 1.0);
+            .content("bar".to_string())
-        assert!((newnote.lastview_date - now).num_minutes() < 1.0);
+            .build()
+            .unwrap();
+        assert!((newnote.creation_date - now).num_minutes() < 1);
+        assert!((newnote.updated_date - now).num_minutes() < 1);
+        assert!((newnote.lastview_date - now).num_minutes() < 1);
         assert!(newnote.deleted_date.is_none());
     }
 }

server/nm-store/src/sql/select_note_collection_from_root.sql

@@ -1,38 +1,87 @@
-SELECT parent_uuid, uuid, content, notetype, nature, position FROM (
+-- This is undoubtedly one of the more complex bits of code I've
+-- written recently, and I do wish there had been macros because
+-- there's a lot of hand-written, copy-pasted code here around the
+-- basic content of a note; it would have been nice to be able to DRY
+-- that out.
 
-    WITH RECURSIVE children(
+-- This expression creates a table, 'notetree', that contains all of
-						parent_id,
+-- the notes nested under a page.  Each entry in the table includes
-						parent_uuid, id,
+-- the note's parent's internal and external ids so that applications
-						uuid,					
+-- can build an actual tree out of a vec of these things.
-						content,
- 						notetype,
- 						creation_date,
-						updated_date,
-						lastview_date,
-						deleted_date,
-						cycle
-		) AS (
 
-         SELECT
+-- TODO: Extensive testing to validate that the nodes are delivered
-			notes.id,
+-- *in nesting order* to the client.
-			notes.uuid,
+
-			notes.id,
+SELECT
-			notes.uuid,
+  parent_id,
-			notes.content,
+  parent_uuid,
-			notes.notetype, 'page', 0, ','||notes.id||','
+  note_id,
-             FROM notes INNER JOIN pages
+  note_uuid,
-                 ON pages.note_id = notes.id
+  content,
-                 WHERE pages.id = ?
+  position,
-                 AND notes.notetype="page"
+  notetype,
+  creation_date,
+  updated_date,
+  lastview_date,
+  deleted_date
+
+FROM (
+
+  WITH RECURSIVE notetree(
+    parent_id,
+    parent_uuid,
+    id,
+    uuid,
+    content,
+    position,
+    notetype,
+    creation_date,
+    updated_date,
+    lastview_date,
+    deleted_date,
+    cycle) AS
+
+-- ROOT expression    
+     SELECT
+       notes.id,
+       notes.uuid,
+       notes.id,
+       notes.uuid,
+       notes.content,
+       0,  -- Root notes are always in position 0
+       notes.notetype,
+       notes.creation_date,
+       notes.updated_date,
+       notes.lastview_date,
+       notes.deleted_date,
+	   ','||notes.id||','  -- Cycle monitor
+     FROM notes
+	   INNER JOIN pages ON pages.note_id = notes.id
+     WHERE
+       pages.slug = ? AND notes.notetype = "root"
+
+-- RECURSIVE expression
+     UNION SELECT
+	   notetree.id,
+	   notetree.uuid,
+	   notes.id,
+	   notes.uuid,
+	   notes.content,
+	   note_relationships.position,
+	   notes.notetype,
+	   notes.creation_date,
+	   notes.updated_date,
+	   notes.lastview_date,
+	   notes.deleted_date,
+	   notetree.cycle||notes.id||','
+	 FROM notes
+	   INNER JOIN note_relationships ON notes.id = note_relationships.note_id
+	   -- For a given ID in the level of notetree in *this* recursion,
+	   -- we want each note's branches one level down.
+	   INNER JOIN notetree ON note_relationships.parent_id = notetree.id
+	   -- And we want to make sure there are no cycles.  There shouldn't
+	   -- be; we're supposed to prevent those.  But you never know.
+	   WHERE
+         notetree.cycle NOT LIKE '%,'||notes.id||',%'
+	   ORDER BY note_relationships.position);
 
-         UNION
-         SELECT note_relationships.parent_id, notes.id,
-                notes.content, notes.notetype, note_relationships.nature,
-                note_relationships.position,
-                children.cycle||notes.id||','
-             FROM notes
-             INNER JOIN note_relationships ON notes.id = note_relationships.note_id
-             INNER JOIN children ON note_relationships.parent_id = children.id
-             WHERE children.cycle NOT LIKE '%,'||notes.id||',%'
-             ORDER BY note_relationships.position)
-    SELECT * from children);</code>

server/nm-store/src/store.rs

@@ -1,11 +1,12 @@
 use crate::errors::NoteStoreError;
-use crate::row_structs::{RawNote, RawPage};
+use crate::row_structs::{JustSlugs, NewNote, NewPage, RawNote, RawPage};
-use chrono;
+use lazy_static::lazy_static;
-use friendly_id;
+use regex::Regex;
+use slug::slugify;
 use sqlx;
 use sqlx::{
     sqlite::{Sqlite, SqlitePool},
-    Done, Executor,
+    Executor,
 };
 use std::sync::Arc;
 
@@ -26,7 +27,7 @@ impl NoteStore {
     // to its original empty form.  Do not use unless you
     // really, really want that to happen.
     pub async fn reset_database(&self) -> NoteResult<()> {
-        reset_databate(&*self.0).await
+        reset_database(&*self.0).await.map_err(NoteStoreError::DBError)
     }
 
     /// Fetch page by slug
@@ -39,6 +40,7 @@ impl NoteStore {
     pub async fn get_page_by_slug(&self, slug: &str) -> NoteResult<(RawPage, Vec<RawNote>)> {
         //		let select_note_collection_for_root = include_str!("sql/select_note_collection_for_root.sql");
         let mut tx = self.0.begin().await?;
+        let page = select_page_by_slug(&mut tx, slug).await?;
         //		let notes = sqlx::query_as(select_note_collection_for_root)
         //			.bind(page.note_id)
         //			.fetch(&tx)
@@ -49,19 +51,17 @@ impl NoteStore {
 
     pub async fn get_page_by_title(&self, title: &str) -> NoteResult<(RawPage, Vec<RawNote>)> {
         let mut tx = self.0.begin().await?;
-        let page = match select_page_by_title(&mut tx, title) {
+        let page = match select_page_by_title(&mut tx, title).await {
-			Ok(page) => page,
+            Ok(page) => page,
-			Err(sqlx::Error::NotFound) => {
+            Err(sqlx::Error::RowNotFound) => match create_page_for_title(&mut tx, title).await {
-				match create_page_for_title(&mut tx, title) {
+                Ok(page) => page,
-					Ok(page) => page,
+                Err(e) => return Err(NoteStoreError::DBError(e))
-					Err(e) => return Err(e)
+            },
-				}
+            Err(e) => return Err(NoteStoreError::DBError(e)),
-			},
+        };
-			Err(e) => return Err(e),
+        // Todo: Replace vec with the results of the CTE
-		};
+        return Ok((page, vec![]));
-		// Todo: Replace vec with the results of the CTE
+    }
-		return Ok((page, vec![]))
-	}
 }
 
 //  ___     _          _
@@ -79,14 +79,14 @@ async fn select_page_by_slug<'e, E>(executor: E, slug: &str) -> SqlResult<RawPag
 where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
-    let select_one_page_by_title_sql = concat!(
+    let select_one_page_by_slug_sql = concat!(
         "SELECT id, title, slug, note_id, creation_date, updated_date, ",
         "lastview_date, deleted_date FROM pages WHERE slug=?;"
     );
-    sqlx::query_as(select_one_page_by_slug_sql)
+    Ok(sqlx::query_as(&select_one_page_by_slug_sql)
         .bind(&slug)
-        .fetch_one(&mut executor)
+        .fetch_one(executor)
-        .await?
+        .await?)
 }
 
 async fn select_page_by_title<'e, E>(executor: E, title: &str) -> SqlResult<RawPage>
@@ -97,10 +97,10 @@ where
         "SELECT id, title, slug, note_id, creation_date, updated_date, ",
         "lastview_date, deleted_date FROM pages WHERE title=?;"
     );
-    sqlx::query_as(select_one_page_by_title_sql)
+    Ok(sqlx::query_as(&select_one_page_by_title_sql)
         .bind(&title)
-        .fetch_one(&mut executor)
+        .fetch_one(executor)
-        .await?
+        .await?)
 }
 
 async fn reset_database<'e, E>(executor: E) -> SqlResult<()>
@@ -108,42 +108,63 @@ where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
     let initialize_sql = include_str!("sql/initialize_database.sql");
-    sqlx::query(initialize_sql).execute(&*self.0).await?
+    sqlx::query(initialize_sql).execute(executor).await.map(|_| ())
 }
 
-async fn get_note_collection_for_root<'e, E>(executor: E, root: i64) -> SqlResult<Vec<RawNotes>>
+async fn get_note_collection_for_root<'e, E>(executor: E, root: i64) -> SqlResult<Vec<RawNote>>
 where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
-    let select_note_collection_for_root = include_str!("sql/select_note_collection_for_root.sql");
+    let select_note_collection_for_root = include_str!("sql/select_note_collection_from_root.sql");
-    sqlx::query_as(select_note_collection_for_root)
+    Ok(sqlx::query_as(&select_note_collection_for_root)
-        .fetch(&*self.0)
+	   .bind(&root)
-        .await?
+       .fetch_all(executor)
+       .await?)
 }
 
-async fn insert_one_new_note<'e, E>(executor: E, note: &NewNote) -> SqlResult<i64> where
+async fn insert_one_new_note<'e, E>(executor: E, note: &NewNote) -> SqlResult<i64>
+where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
-	let insert_one_note_sql = concat!(
+    let insert_one_note_sql = concat!(
-		"INSERT INTO notes ( ",
+        "INSERT INTO notes ( ",
-		"	   uuid, ",
+        "	   uuid, ",
-		"	   content, ",
+        "	   content, ",
-		"	   notetype, ",
+        "	   notetype, ",
-		"	   creation_date, ",
+        "	   creation_date, ",
-		"	   updated_date, ",
+        "	   updated_date, ",
-		"	   lastview_date) ",
+        "	   lastview_date) ",
-		"VALUES (?, ?, ?, ?, ?, ?);");
+        "VALUES (?, ?, ?, ?, ?, ?);"
-	
+    );
+
     Ok(sqlx::query(insert_one_note_sql)
-       .bind(&note.uuid)
+        .bind(&note.uuid)
-       .bind(&note.content)
+        .bind(&note.content)
-       .bind(&note.note_type)
+        .bind(&note.notetype)
-       .bind(&note.creation_date)
+        .bind(&note.creation_date)
-       .bind(&note.updated_date)
+        .bind(&note.updated_date)
-       .bind(&note.lastview_date)
+        .bind(&note.lastview_date)
-       .execute(&mut tx)
+        .execute(executor)
-       .await?
+        .await?
-	   .last_insert_rowid())
+        .last_insert_rowid())
+}
+
+fn find_maximal_slug(slugs: &Vec<JustSlugs>) -> Option<u32> {
+    lazy_static! {
+        static ref RE_CAP_NUM: Regex = Regex::new(r"-(\d+)$").unwrap();
+    }
+
+    if slugs.len() == 0 {
+        return None;
+    }
+
+    let mut slug_counters: Vec<u32> = slugs
+        .iter()
+        .filter_map(|slug| RE_CAP_NUM.captures(&slug.slug))
+        .map(|cap| cap.get(1).unwrap().as_str().parse::<u32>().unwrap())
+        .collect();
+    slug_counters.sort_unstable();
+    slug_counters.pop()
 }
 
 // Given an initial string and an existing collection of slugs,
@@ -156,28 +177,19 @@ where
     lazy_static! {
         static ref RE_STRIP_NUM: Regex = Regex::new(r"-\d+$").unwrap();
     }
-	lazy_static! {
-		static ref RE_CAP_NUM: Regex = Regex::new(r"-(\d+)$").unwrap();
-	}
 
-	let initial_slug = slugify::slugify(title);
+    let initial_slug = slugify(title);
-	let sample_slug = RE_STRIP_NUM.replace_all(slug, "");
+    let sample_slug = RE_STRIP_NUM.replace_all(&initial_slug, "");
-	let similar_slugs: Vec<JustSlugs> = sqlx::query("SELECT slug FROM pages WHERE slug LIKE '?%';")
+	let slug_finder_sql = "SELECT slug FROM pages WHERE slug LIKE '?%';";
-		.bind(&sample_slug)
+    let similar_slugs: Vec<JustSlugs> = sqlx::query_as(&slug_finder_sql)
-		.execute(executor)
+        .bind(&*sample_slug)
-		.await?;
+        .fetch_all(executor)
-	let slug_counters = similar_slugs
+        .await?;
-		.iter()
+    let maximal_slug = find_maximal_slug(&similar_slugs);
-		.map(|slug| RE_CAPNUM.captures(slug.slug))
+    match maximal_slug {
-		.filter_map(|cap| cap.get(1).unwrap().parse::<u32>().unwrap())
+        None => Ok(initial_slug),
-		.collect();
+        Some(max_slug) => Ok(format!("{}-{}", initial_slug, max_slug + 1)),
-	match slug_counters.len() {
+    }
-		0 => Ok(initial_slug),
-		_ => {
-			slug_counters.sort_unstable();
-			return Ok(format!("{}-{}", initial_slug, slug_counters.pop() + 1))
-		}
-	}
 }
 
 async fn insert_one_new_page<'e, E>(executor: E, page: &NewPage) -> SqlResult<i64>
@@ -185,30 +197,31 @@ where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
     let insert_one_page_sql = concat!(
-		"INSERT INTO pages ( ",
+        "INSERT INTO pages ( ",
-		"	   slug, ",
+        "	   slug, ",
-		"	   title, ",
+        "	   title, ",
-		"	   note_id, ",
+        "	   note_id, ",
-		"	   creation_date, ",
+        "	   creation_date, ",
-		"	   updated_date, ",
+        "	   updated_date, ",
-		"	   lastview_date) ",
+        "	   lastview_date) ",
-		"VALUES (?, ?, ?, ?, ?, ?);");
+        "VALUES (?, ?, ?, ?, ?, ?);"
+    );
 
     Ok(sqlx::query(insert_one_page_sql)
-       .bind(&page.slug)
+        .bind(&page.slug)
-       .bind(&page.title)
+        .bind(&page.title)
-       .bind(&page.note_id)
+        .bind(&page.note_id)
-       .bind(&page.creation_date)
+        .bind(&page.creation_date)
-       .bind(&page.updated_date)
+        .bind(&page.updated_date)
-       .bind(&page.lastview_date)
+        .bind(&page.lastview_date)
-       .execute(&mut tx)
+        .execute(executor)
-       .await?
+        .await?
-	   .last_insert_rowid())
+        .last_insert_rowid())
 }
-	
 
-async fn create_page_for_title<'e, E>(executor: E, title: &str) -> SqlResult<RawPage> where
+async fn create_page_for_title<'e, E>(_executor: E, _title: &str) -> SqlResult<RawPage>
+where
     E: 'e + Executor<'e, Database = Sqlite>,
 {
-	todo!()
+    todo!()
 }