diff --git a/src/currentprocess/filesource.rs b/src/currentprocess/filesource.rs
index 9546d6d8e4..c5be4b180e 100644
--- a/src/currentprocess/filesource.rs
+++ b/src/currentprocess/filesource.rs
@@ -1,9 +1,4 @@
 use std::io::{self, BufRead, Read, Result, Write};
-#[cfg(feature = "test")]
-use std::{
-    io::Cursor,
-    sync::{Arc, Mutex, MutexGuard},
-};
 
 use enum_dispatch::enum_dispatch;
 
@@ -45,58 +40,6 @@ impl StdinSource for super::OSProcess {
     }
 }
 
-// ----------------------- test support for stdin ------------------
-
-#[cfg(feature = "test")]
-struct TestStdinLock<'a> {
-    inner: MutexGuard<'a, Cursor<String>>,
-}
-
-#[cfg(feature = "test")]
-impl StdinLock for TestStdinLock<'_> {}
-
-#[cfg(feature = "test")]
-impl Read for TestStdinLock<'_> {
-    fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
-        self.inner.read(buf)
-    }
-}
-
-#[cfg(feature = "test")]
-impl BufRead for TestStdinLock<'_> {
-    fn fill_buf(&mut self) -> io::Result<&[u8]> {
-        self.inner.fill_buf()
-    }
-    fn consume(&mut self, n: usize) {
-        self.inner.consume(n)
-    }
-}
-
-#[cfg(feature = "test")]
-pub(crate) type TestStdinInner = Arc<Mutex<Cursor<String>>>;
-
-#[cfg(feature = "test")]
-struct TestStdin(TestStdinInner);
-
-#[cfg(feature = "test")]
-impl Stdin for TestStdin {
-    fn lock(&self) -> Box<dyn StdinLock + '_> {
-        Box::new(TestStdinLock {
-            inner: self.0.lock().unwrap_or_else(|e| e.into_inner()),
-        })
-    }
-    fn read_line(&self, buf: &mut String) -> Result<usize> {
-        self.lock().read_line(buf)
-    }
-}
-
-#[cfg(feature = "test")]
-impl StdinSource for super::TestProcess {
-    fn stdin(&self) -> Box<dyn Stdin> {
-        Box::new(TestStdin(self.stdin.clone()))
-    }
-}
-
 // -------------- stdout -------------------------------
 
 /// This is a stand-in for [`std::io::StdoutLock`] and [`std::io::StderrLock`].
@@ -187,81 +130,129 @@ impl StderrSource for super::OSProcess {
     }
 }
 
-// ----------------------- test support for writers ------------------
-
 #[cfg(feature = "test")]
-pub(super) struct TestWriterLock<'a> {
-    inner: MutexGuard<'a, Vec<u8>>,
-}
+pub(crate) use self::test_support::*;
 
 #[cfg(feature = "test")]
-impl WriterLock for TestWriterLock<'_> {}
+mod test_support {
+    use std::{
+        io::Cursor,
+        sync::{Arc, Mutex, MutexGuard},
+    };
 
-#[cfg(feature = "test")]
-impl Write for TestWriterLock<'_> {
-    fn write(&mut self, buf: &[u8]) -> Result<usize> {
-        self.inner.write(buf)
+    use super::{super::TestProcess, *};
+
+    // ----------------------- test support for stdin ------------------
+
+    struct TestStdinLock<'a> {
+        inner: MutexGuard<'a, Cursor<String>>,
     }
 
-    fn flush(&mut self) -> Result<()> {
-        Ok(())
+    impl StdinLock for TestStdinLock<'_> {}
+
+    impl Read for TestStdinLock<'_> {
+        fn read(&mut self, buf: &mut [u8]) -> io::Result<usize> {
+            self.inner.read(buf)
+        }
     }
-}
 
-#[cfg(feature = "test")]
-pub(super) type TestWriterInner = Arc<Mutex<Vec<u8>>>;
-/// A thread-safe test file handle that pretends to be e.g. stdout.
-#[derive(Clone, Default)]
-#[cfg(feature = "test")]
-pub(super) struct TestWriter(TestWriterInner);
+    impl BufRead for TestStdinLock<'_> {
+        fn fill_buf(&mut self) -> io::Result<&[u8]> {
+            self.inner.fill_buf()
+        }
+        fn consume(&mut self, n: usize) {
+            self.inner.consume(n)
+        }
+    }
 
-#[cfg(feature = "test")]
-impl TestWriter {
-    pub(super) fn lock(&self) -> TestWriterLock<'_> {
-        // The stream can be locked even if a test thread panicked: its state
-        // will be ok
-        TestWriterLock {
-            inner: self.0.lock().unwrap_or_else(|e| e.into_inner()),
+    pub(crate) type TestStdinInner = Arc<Mutex<Cursor<String>>>;
+
+    struct TestStdin(TestStdinInner);
+
+    impl Stdin for TestStdin {
+        fn lock(&self) -> Box<dyn StdinLock + '_> {
+            Box::new(TestStdinLock {
+                inner: self.0.lock().unwrap_or_else(|e| e.into_inner()),
+            })
+        }
+        fn read_line(&self, buf: &mut String) -> Result<usize> {
+            self.lock().read_line(buf)
         }
     }
-}
 
-#[cfg(feature = "test")]
-impl Writer for TestWriter {
-    fn is_a_tty(&self) -> bool {
-        false
+    impl StdinSource for TestProcess {
+        fn stdin(&self) -> Box<dyn Stdin> {
+            Box::new(TestStdin(self.stdin.clone()))
+        }
     }
 
-    fn lock(&self) -> Box<dyn WriterLock + '_> {
-        Box::new(self.lock())
+    // ----------------------- test support for writers ------------------
+
+    pub(in super::super) struct TestWriterLock<'a> {
+        inner: MutexGuard<'a, Vec<u8>>,
     }
 
-    fn terminal(&self) -> ColorableTerminal {
-        ColorableTerminal::new(StreamSelector::TestWriter(self.clone()))
+    impl WriterLock for TestWriterLock<'_> {}
+
+    impl Write for TestWriterLock<'_> {
+        fn write(&mut self, buf: &[u8]) -> Result<usize> {
+            self.inner.write(buf)
+        }
+
+        fn flush(&mut self) -> Result<()> {
+            Ok(())
+        }
     }
-}
 
-#[cfg(feature = "test")]
-impl Write for TestWriter {
-    fn write(&mut self, buf: &[u8]) -> Result<usize> {
-        self.lock().write(buf)
+    pub(in super::super) type TestWriterInner = Arc<Mutex<Vec<u8>>>;
+
+    /// A thread-safe test file handle that pretends to be e.g. stdout.
+    #[derive(Clone, Default)]
+    pub(in super::super) struct TestWriter(TestWriterInner);
+
+    impl TestWriter {
+        pub(in super::super) fn lock(&self) -> TestWriterLock<'_> {
+            // The stream can be locked even if a test thread panicked: its state
+            // will be ok
+            TestWriterLock {
+                inner: self.0.lock().unwrap_or_else(|e| e.into_inner()),
+            }
+        }
     }
 
-    fn flush(&mut self) -> Result<()> {
-        Ok(())
+    impl Writer for TestWriter {
+        fn is_a_tty(&self) -> bool {
+            false
+        }
+
+        fn lock(&self) -> Box<dyn WriterLock + '_> {
+            Box::new(self.lock())
+        }
+
+        fn terminal(&self) -> ColorableTerminal {
+            ColorableTerminal::new(StreamSelector::TestWriter(self.clone()))
+        }
     }
-}
 
-#[cfg(feature = "test")]
-impl StdoutSource for super::TestProcess {
-    fn stdout(&self) -> Box<dyn Writer> {
-        Box::new(TestWriter(self.stdout.clone()))
+    impl Write for TestWriter {
+        fn write(&mut self, buf: &[u8]) -> Result<usize> {
+            self.lock().write(buf)
+        }
+
+        fn flush(&mut self) -> Result<()> {
+            Ok(())
+        }
     }
-}
 
-#[cfg(feature = "test")]
-impl StderrSource for super::TestProcess {
-    fn stderr(&self) -> Box<dyn Writer> {
-        Box::new(TestWriter(self.stderr.clone()))
+    impl StdoutSource for TestProcess {
+        fn stdout(&self) -> Box<dyn Writer> {
+            Box::new(TestWriter(self.stdout.clone()))
+        }
+    }
+
+    impl StderrSource for TestProcess {
+        fn stderr(&self) -> Box<dyn Writer> {
+            Box::new(TestWriter(self.stderr.clone()))
+        }
     }
 }