From b67c534ac43e90fca27872ee6b39a61416d52f69 Mon Sep 17 00:00:00 2001
From: Sergio Machado <machadosergio@gmail.com>
Date: Fri, 13 Jun 2025 19:39:52 -0400
Subject: [PATCH] Set tags filter via environment variable

---
 Cargo.toml               |  2 +-
 book/src/cli.md          |  2 ++
 book/src/writing/tags.md |  2 +-
 src/cli.rs               |  1 +
 tests/cli.rs             | 34 +++++++++++++++++++++++++++++++++-
 5 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/Cargo.toml b/Cargo.toml
index c390606b..98fec84b 100644
--- a/Cargo.toml
+++ b/Cargo.toml
@@ -64,7 +64,7 @@ timestamps = []
 tracing = ["dep:crossbeam-utils", "dep:tracing", "dep:tracing-subscriber"]
 
 [dependencies]
-clap = { version = "4.3.2", features = ["derive", "wrap_help"] }
+clap = { version = "4.3.2", features = ["derive", "wrap_help", "env"] }
 console = "0.15"
 derive_more = { version = "2.0", features = ["as_ref", "debug", "deref", "deref_mut", "display", "error", "from", "from_str", "into"] }
 either = "1.6"
diff --git a/book/src/cli.md b/book/src/cli.md
index cd949a88..9aa74875 100644
--- a/book/src/cli.md
+++ b/book/src/cli.md
@@ -24,6 +24,8 @@ Options:
           Tag expression to filter scenarios by.
           
           Note: Tags from Feature, Rule and Scenario are merged together on filtering, so be careful about conflicting tags on different levels.
+          
+          [env: CUCUMBER_FILTER_TAGS=@scenario-1]
 
   -i, --input <glob>
           Glob pattern to look for feature files with. If not specified, looks for `*.feature` files in the path configured in the test runner
diff --git a/book/src/writing/tags.md b/book/src/writing/tags.md
index 662f9484..1eaa07bb 100644
--- a/book/src/writing/tags.md
+++ b/book/src/writing/tags.md
@@ -31,7 +31,7 @@ Feature: Animal feature
 ```
 
 To filter out running [scenario]s we may use:
-- either `--tags` [CLI] option providing [tag expressions] (also consider [escaping]);
+- either `--tags` [CLI] option providing [tag expressions] (also consider [escaping]). The expression can alternatively also be set using the `CUCUMBER_FILTER_TAGS` environment variable.
 - or [`filter_run()`]-like method.
 
 ![record](../rec/writing_tags_filtering.gif)
diff --git a/src/cli.rs b/src/cli.rs
index a7c49db9..3a5423b7 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -109,6 +109,7 @@ where
         id = "tags",
         long = "tags",
         short = 't',
+        env = "CUCUMBER_FILTER_TAGS",
         value_name = "tagexpr",
         conflicts_with = "name",
         global = true
diff --git a/tests/cli.rs b/tests/cli.rs
index 0bf10eb5..db38232e 100644
--- a/tests/cli.rs
+++ b/tests/cli.rs
@@ -1,4 +1,4 @@
-use std::panic::AssertUnwindSafe;
+use std::{env, panic::AssertUnwindSafe};
 
 use clap::Parser;
 use cucumber::{World as _, cli, given};
@@ -92,3 +92,35 @@ async fn tags_option_filters_scenario1_no_subcommand() {
 
     assert_eq!(err, "1 step failed");
 }
+
+// This test verifies that the global option `--tags` is still available without
+// subcommands and that the error output contains 1 failing step.
+// (env variable variant)
+#[test]
+fn tags_option_filters_scenario1_no_subcommand_env() {
+    unsafe {
+        env::set_var("CUCUMBER_FILTER_TAGS", "@scenario-1");
+    }
+
+    tokio::runtime::Builder::new_current_thread()
+        .enable_all()
+        .build()
+        .unwrap()
+        .block_on(async {
+            let cli =
+                cli::Opts::<_, _, _, CustomCli>::try_parse_from(&["test"])
+                    .expect("Invalid command line");
+
+            let res = World::cucumber()
+                .with_cli(cli)
+                .run_and_exit("tests/features/cli");
+
+            let err = AssertUnwindSafe(res)
+                .catch_unwind()
+                .await
+                .expect_err("should err");
+            let err = err.downcast_ref::<String>().unwrap();
+
+            assert_eq!(err, "1 step failed");
+        })
+}