dx: quiet Bazel progress when stdout is not a terminal

cli/cli/src/main.rs

@@ -8,7 +8,7 @@
     )
 )]
 
-use std::io::{self, Write};
+use std::io::{self, IsTerminal, Write};
 use std::path::Path;
 
 use dx_cli::bazel_restart::{RestartingQueryRunner, RestartingRunner};
@@ -248,6 +248,7 @@ fn run() -> i32 {
             return usage_error(code, &error.to_string(), json, command);
         }
     };
+    invocation.piped = !io::stdout().is_terminal();
     // LCOV_EXCL_STOP - reason: end thin run shim, issue: 1055, policy: docs/cli/commands/build-test-coverage.md
     dx_adopt::refresh_stale_pins_from_env();
     dx_cli::exec::set_usage_command(invocation.command);

cli/plan/src/args/invocation.rs

@@ -334,6 +334,8 @@ pub struct Invocation {
     pub bench_compare: Option<String>,
     pub path_only: bool,
     pub agent: bool,
+    /// Stdout is not a terminal.
+    pub piped: bool,
     pub bazel_startup_options: Vec<String>,
 }
 
@@ -352,9 +354,10 @@ impl Invocation {
         self.command == Command::Update && self.targets.len() == 2 && is_version(&self.targets[1])
     }
 
-    /// Bazel UI flags that silence progress output in agent JSON sessions.
+    /// Bazel UI flags that silence progress output in agent JSON sessions and piped runs; `-v` keeps Bazel output.
     pub fn agent_quiet_flags(&self) -> Vec<String> {
-        if self.agent && self.output == OutputMode::Json {
+        let agent_json = self.agent && self.output == OutputMode::Json;
+        if (agent_json || self.piped) && !self.verbose {
             AGENT_QUIET_FLAGS
                 .iter()
                 .map(|flag| (*flag).to_owned())
@@ -364,7 +367,7 @@ impl Invocation {
         }
     }
 
-    /// Bazel options for the run: agent JSON sessions get no progress output.
+    /// Bazel options for the run: agent JSON sessions and piped runs get no progress output.
     pub fn quiet_bazel_options(&self) -> Vec<String> {
         let mut options = self.agent_quiet_flags();
         options.extend(self.bazel_options.iter().cloned());
@@ -743,6 +746,7 @@ mod tests {
             bench_compare: None,
             path_only: false,
             agent: false,
+            piped: false,
             bazel_startup_options: Vec::new(),
         }
     }
@@ -1117,6 +1121,16 @@ mod tests {
         AGENT_QUIET_FLAGS.iter().map(ToString::to_string).collect()
     }
 
+    #[test]
+    fn piped_runs_are_quiet_unless_verbose() {
+        let mut inv = parsed(&["build"]);
+        assert!(inv.quiet_bazel_options().is_empty());
+        inv.piped = true;
+        assert_eq!(inv.quiet_bazel_options(), quiet_flags());
+        inv.verbose = true;
+        assert!(inv.quiet_bazel_options().is_empty());
+    }
+
     #[test]
     fn raw_bazel_options_never_carry_agent_quiet_flags() {
         let session = agent(&["build", "--output=json", "--", "--jobs=4"]);
@@ -1146,6 +1160,20 @@ mod tests {
         );
     }
 
+    #[test]
+    fn piped_requests_carry_quiet_flags_until_verbose() {
+        let mut inv = parsed(&["generate", "--", "--jobs=4"]);
+        inv.piped = true;
+        let mut want = quiet_flags();
+        want.push("--jobs=4".to_owned());
+        assert_eq!(inv.generate_request().expect("generate").bazel_options, want);
+        inv.verbose = true;
+        assert_eq!(
+            inv.generate_request().expect("generate").bazel_options,
+            vec!["--jobs=4".to_owned()]
+        );
+    }
+
     #[test]
     fn agent_quiet_generate_request_puts_quiet_flags_before_the_callers_options() {
         let generate = agent(&["generate", "--output=json", "--", "--jobs=4"])

cli/plan/src/args/parser.rs

@@ -747,6 +747,7 @@ fn parse_inner<S: AsRef<OsStr>>(
         bench_compare: compare,
         path_only,
         agent,
+        piped: false,
         bazel_startup_options,
     })
 }

docs/cli/commands/build-test-coverage.md

@@ -46,6 +46,8 @@ dx coverage [--here] [--affected] [--timings] [--min-coverage <percent>] [--min-
 
 `--debug` and `--release` conflict. Both change compilation only.
 
+When stdout is not a terminal, dx passes Bazel the quiet flags `--noshow_progress`, `--noshow_loading_progress`, `--noshow_timestamps`, `--curses=no`, `--ui_event_filters=-info,-debug` and `--test_summary=none`. `-v` keeps full Bazel output.
+
 ## Scopes
 
 No scope means `//...`. Pass labels, patterns, files, or directories. A file runs its owning targets. For `test` and `coverage`, a file runs the tests that depend on its owners. A `manual` test runs only when it owns the file.