From 23070683fc3b247380ceeed20d984fa5b63fb226 Mon Sep 17 00:00:00 2001
From: matt-hagemann <matt.hagemann@canonical.com>
Date: Tue, 28 Nov 2023 16:01:58 +0200
Subject: [PATCH] feat: only return top 20 in charts

---
 example.env                         |  2 +-
 src/features/chart/entities.rs      |  5 ++-
 tests/chart_tests/lifecycle_test.rs | 50 ++++++++++++++---------------
 3 files changed, 29 insertions(+), 28 deletions(-)

diff --git a/example.env b/example.env
index 0a385dbd..9eac6810 100644
--- a/example.env
+++ b/example.env
@@ -1,7 +1,7 @@
 APP_ENV=dev
 APP_HOST=0.0.0.0
 APP_JWT_SECRET=deadbeef
-APP_LOG_LEVEL=info
+APP_LOG_LEVEL=error
 APP_NAME=ratings
 APP_PORT=8080
 # Update this with some real PostgreSQL details
diff --git a/src/features/chart/entities.rs b/src/features/chart/entities.rs
index 10e7212c..7bb9d345 100644
--- a/src/features/chart/entities.rs
+++ b/src/features/chart/entities.rs
@@ -19,9 +19,12 @@ impl Chart {
                 .unwrap_or(std::cmp::Ordering::Equal)
         });
 
+        // Take only the first 20 elements from the sorted chart_data
+        let top_20: Vec<ChartData> = chart_data.into_iter().take(20).collect();
+
         Chart {
             timeframe,
-            chart_data,
+            chart_data: top_20,
         }
     }
 }
diff --git a/tests/chart_tests/lifecycle_test.rs b/tests/chart_tests/lifecycle_test.rs
index 78819111..9dd9bc40 100644
--- a/tests/chart_tests/lifecycle_test.rs
+++ b/tests/chart_tests/lifecycle_test.rs
@@ -44,12 +44,15 @@ async fn chart_lifecycle_test() -> Result<(), Box<dyn std::error::Error>> {
 // Does an app voted against once appear correctly in the chart?
 async fn vote_once(mut data: TestData) -> TestData {
     let vote_up = true;
-    let expected_raw_rating = 0.0;
-    let expected_rating = Rating {
-        snap_id: data.snap_id.clone().unwrap(),
-        total_votes: 1,
-        ratings_band: RatingsBand::InsufficientVotes.into(),
-    };
+
+    // Fill up chart with other votes so ours doesn't appear
+    for _ in 0..20 {
+        generate_votes(&data_faker::rnd_id(), 111, vote_up, 25, data.clone())
+            .await
+            .expect("Votes should succeed");
+    }
+
+    let vote_up = true;
 
     generate_votes(
         &data.snap_id.clone().unwrap(),
@@ -89,11 +92,8 @@ async fn vote_once(mut data: TestData) -> TestData {
         }
     });
 
-    let actual_rating = result.clone().unwrap().rating.unwrap();
-    let actual_raw_rating = result.unwrap().raw_rating;
-
-    assert_eq!(expected_rating, actual_rating);
-    assert_eq!(expected_raw_rating, actual_raw_rating);
+    // Should not appear in chart
+    assert_eq!(result, None);
 
     data
 }
@@ -104,15 +104,16 @@ async fn multiple_votes(mut data: TestData) -> TestData {
     let expected_raw_rating = 0.8;
     let expected_rating = Rating {
         snap_id: data.snap_id.clone().unwrap(),
-        total_votes: 25,
+        total_votes: 101,
         ratings_band: RatingsBand::VeryGood.into(),
     };
 
+    // This should rank our snap_id at the top of the chart
     generate_votes(
         &data.snap_id.clone().unwrap(),
         111,
         vote_up,
-        24,
+        100,
         data.clone(),
     )
     .await
@@ -138,19 +139,16 @@ async fn multiple_votes(mut data: TestData) -> TestData {
         .into_inner()
         .ordered_chart_data;
 
-    let result = chart_data_result.into_iter().find(|chart_data| {
-        if let Some(rating) = &chart_data.rating {
-            rating.snap_id == data.snap_id.clone().unwrap()
-        } else {
-            false
-        }
-    });
+    // Should be at the top of the chart
+    if let Some(chart_data) = chart_data_result.first() {
+        let actual_rating = chart_data.rating.clone().expect("Rating should exist");
+        let actual_raw_rating = chart_data.raw_rating;
 
-    let actual_rating = result.clone().unwrap().rating.unwrap();
-    let actual_raw_rating = result.unwrap().raw_rating;
-
-    assert_eq!(expected_rating, actual_rating);
-    assert!(expected_raw_rating < actual_raw_rating);
+        assert_eq!(expected_rating, actual_rating);
+        assert!(expected_raw_rating < actual_raw_rating);
+    } else {
+        panic!("No chart data available");
+    }
 
     data
 }
@@ -200,7 +198,7 @@ async fn timeframed_votes_dont_appear(mut data: TestData) -> TestData {
     let expected_raw_rating = 0.8;
     let expected_rating = Rating {
         snap_id: data.snap_id.clone().unwrap(),
-        total_votes: 25,
+        total_votes: 101,
         ratings_band: RatingsBand::VeryGood.into(),
     };