feat(events): Add --json output to events dropped

CHANGELOG.md

@@ -5,6 +5,7 @@
 ### Features
 
 - (events) Add `events dropped` command to summarize dropped events by outcome and reason ([#3431](https://github.com/getsentry/sentry-cli/pull/3431))
+- (events) Add `--json` output to `events dropped` ([#3432](https://github.com/getsentry/sentry-cli/pull/3432))
 
 ## 3.8.0
 

src/commands/events/dropped.rs

@@ -1,7 +1,9 @@
 use std::collections::BTreeMap;
+use std::io;
 
 use anyhow::Result;
-use clap::{Arg, ArgMatches, Command};
+use clap::{Arg, ArgAction, ArgMatches, Command};
+use serde::Serialize;
 
 use crate::api::{outcome_label, Api, DroppedEventsBucket};
 use crate::config::Config;
@@ -27,54 +29,83 @@ pub fn make_command(command: Command) -> Command {
                 .default_value("90d")
                 .help("Time range to summarize (e.g. 24h, 14d, 90d)."),
         )
+        .arg(
+            Arg::new("json")
+                .long("json")
+                .action(ArgAction::SetTrue)
+                .help("Output the summary as JSON (for agents/automation)."),
+        )
 }
 
+#[derive(Serialize)]
 struct ReasonRow {
     reason: String,
     category: String,
     events: u64,
+    share: f64,
 }
 
+#[derive(Serialize)]
 struct OutcomeSection {
     outcome: String,
+    label: String,
     events: u64,
+    share: f64,
     reasons: Vec<ReasonRow>,
 }
 
-fn format_share(events: u64, total: u64) -> String {
+fn share_ratio(events: u64, total: u64) -> f64 {
     if total == 0 {
-        return "0%".to_owned();
+        0.0
+    } else {
+        events as f64 / total as f64
     }
-    let ratio = events as f64 / total as f64;
+}
+
+fn format_share(ratio: f64) -> String {
     if ratio > 0.0 && ratio < 0.0001 {
         return "<0.01%".to_owned();
     }
     format!("{:.2}%", ratio * 100.0)
 }
 
-fn to_sections(dropped: &[DroppedEventsBucket]) -> Vec<OutcomeSection> {
-    let mut by_outcome: BTreeMap<String, BTreeMap<String, ReasonRow>> = BTreeMap::new();
+struct ReasonTotals {
+    category: String,
+    events: u64,
+}
+
+fn to_sections(dropped: &[DroppedEventsBucket], total: u64) -> Vec<OutcomeSection> {
+    let mut by_outcome: BTreeMap<String, BTreeMap<String, ReasonTotals>> = BTreeMap::new();
     for bucket in dropped {
         let reasons = by_outcome.entry(bucket.outcome.clone()).or_default();
-        let row = reasons
+        let totals = reasons
             .entry(bucket.reason.clone())
-            .or_insert_with(|| ReasonRow {
-                reason: bucket.reason.clone(),
+            .or_insert_with(|| ReasonTotals {
                 category: bucket.category.clone(),
                 events: 0,
             });
-        row.events += bucket.count as u64;
+        totals.events += bucket.count as u64;
     }
 
     let mut sections: Vec<OutcomeSection> = by_outcome
         .into_iter()
         .map(|(outcome, reasons)| {
-            let mut reasons: Vec<ReasonRow> = reasons.into_values().collect();
+            let mut reasons: Vec<ReasonRow> = reasons
+                .into_iter()
+                .map(|(reason, t)| ReasonRow {
+                    reason,
+                    category: t.category,
+                    events: t.events,
+                    share: share_ratio(t.events, total),
+                })
+                .collect();
             reasons.sort_by_key(|r| std::cmp::Reverse(r.events));
             let events = reasons.iter().map(|r| r.events).sum();
             OutcomeSection {
+                label: outcome_label(&outcome).to_owned(),
                 outcome,
                 events,
+                share: share_ratio(events, total),
                 reasons,
             }
         })
@@ -107,7 +138,14 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
         .map(|b| b.count as u64)
         .sum();
 
-    let sections = to_sections(&response.dropped_events);
+    let sections = to_sections(&response.dropped_events, total);
+
+    if matches.get_flag("json") {
+        serde_json::to_writer_pretty(&mut io::stdout(), &sections)?;
+        println!();
+        return Ok(());
+    }
+
     if sections.is_empty() {
         println!("No dropped events found");
         return Ok(());
@@ -116,9 +154,9 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
     for section in &sections {
         println!(
             "\n{}: {} dropped ({})",
-            outcome_label(&section.outcome),
+            section.label,
             section.events,
-            format_share(section.events, total),
+            format_share(section.share),
         );
 
         let mut table = Table::new();
@@ -134,7 +172,7 @@ pub fn execute(matches: &ArgMatches) -> Result<()> {
                 .add(&row.reason)
                 .add(&row.category)
                 .add(row.events)
-                .add(format_share(row.events, total));
+                .add(format_share(row.share));
         }
         table.print();
     }

tests/integration/_cases/events_dropped/events-dropped-json.trycmd

@@ -0,0 +1,55 @@
+```
+$ sentry-cli events dropped --org wat-org --project wat-project --json
+? success
+[
+  {
+    "outcome": "client_discard",
+    "label": "Client Discard",
+    "events": 100,
+    "share": 0.1,
+    "reasons": [
+      {
+        "reason": "sample_rate",
+        "category": "error",
+        "events": 100,
+        "share": 0.1
+      }
+    ]
+  },
+  {
+    "outcome": "rate_limited",
+    "label": "Rate Limited",
+    "events": 17,
+    "share": 0.017,
+    "reasons": [
+      {
+        "reason": "spike_protection",
+        "category": "error",
+        "events": 15,
+        "share": 0.015
+      },
+      {
+        "reason": "usage_exceeded",
+        "category": "error",
+        "events": 2,
+        "share": 0.002
+      }
+    ]
+  },
+  {
+    "outcome": "filtered",
+    "label": "Inbound Filter",
+    "events": 3,
+    "share": 0.003,
+    "reasons": [
+      {
+        "reason": "web-crawlers",
+        "category": "error",
+        "events": 3,
+        "share": 0.003
+      }
+    ]
+  }
+]
+
+```

tests/integration/events_dropped.rs

@@ -28,6 +28,20 @@ fn command_events_dropped_project_id() {
         .with_default_token();
 }
 
+#[test]
+fn command_events_dropped_json() {
+    TestManager::new()
+        .mock_endpoint(
+            MockEndpointBuilder::new(
+                "GET",
+                "/api/0/organizations/wat-org/events-dropped/?projectSlug=wat-project&dataset=errors&statsPeriod=90d",
+            )
+            .with_response_file("events/get-dropped.json"),
+        )
+        .register_trycmd_test("events_dropped/events-dropped-json.trycmd")
+        .with_default_token();
+}
+
 #[test]
 fn command_events_dropped_empty() {
     TestManager::new()