fix: Fix moon query projects --affected hanging. (#629)

* Fix stdin.

* Add checks.

* Bump version.

.yarn/versions/4b71d12a.yml

@@ -0,0 +1,9 @@
+releases:
+  "@moonrepo/cli": patch
+  "@moonrepo/core-linux-arm64-gnu": patch
+  "@moonrepo/core-linux-arm64-musl": patch
+  "@moonrepo/core-linux-x64-gnu": patch
+  "@moonrepo/core-linux-x64-musl": patch
+  "@moonrepo/core-macos-arm64": patch
+  "@moonrepo/core-macos-x64": patch
+  "@moonrepo/core-windows-x64-msvc": patch

crates/cli/Cargo.toml

@@ -41,6 +41,7 @@ moon_typescript_lang = { path = "../typescript/lang" }
 moon_utils = { path = "../core/utils" }
 moon_vcs = { path = "../core/vcs" }
 moon_workspace = { path = "../core/workspace" }
+atty = "0.2.14"
 bytes = "1.4.0"
 clap = { workspace = true, features = ["derive", "env", "wrap_help"] }
 clap_complete = { workspace = true }

crates/cli/src/commands/query.rs

@@ -26,7 +26,7 @@ pub async fn projects(options: &QueryProjectsOptions) -> Result<(), AnyError> {
         };
 
         writeln!(stdout, "{}", serde_json::to_string_pretty(&result)?)?;
-    } else {
+    } else if !projects.is_empty() {
         writeln!(
             stdout,
             "{}",
@@ -55,7 +55,7 @@ pub async fn touched_files(options: &mut QueryTouchedFilesOptions) -> Result<(),
         };
 
         writeln!(stdout, "{}", serde_json::to_string_pretty(&result)?)?;
-    } else {
+    } else if !files.is_empty() {
         writeln!(
             stdout,
             "{}",
@@ -84,7 +84,7 @@ pub async fn tasks(options: &QueryProjectsOptions) -> Result<(), AnyError> {
         };
 
         writeln!(stdout, "{}", serde_json::to_string_pretty(&result)?)?;
-    } else {
+    } else if !projects.is_empty() {
         for project in projects {
             if project.tasks.is_empty() {
                 continue;

crates/cli/src/queries/projects.rs

@@ -65,7 +65,11 @@ fn convert_to_regex(field: &str, value: &Option<String>) -> Result<Option<regex:
 async fn load_touched_files(workspace: &Workspace) -> Result<TouchedFilePaths, WorkspaceError> {
     let mut buffer = String::new();
 
-    stdin().read_to_string(&mut buffer).map_err(MoonError::Io)?;
+    // Only read piped data when stdin is not a TTY,
+    // otherwise the process will hang indefinitely waiting for EOF.
+    if atty::isnt(atty::Stream::Stdin) {
+        stdin().read_to_string(&mut buffer).map_err(MoonError::Io)?;
+    }
 
     // If piped via stdin, parse and use it
     if !buffer.is_empty() {

packages/cli/CHANGELOG.md

@@ -1,5 +1,11 @@
 # Changelog
 
+## Unreleased
+
+#### 🐞 Fixes
+
+- Fixed an issue where `moon query projects --affected` would hang indefinitely waiting for stdin.
+
 ## 0.24.2
 
 #### 🚀 Updates