rage: Allow piping input when encrypting with passphrase on Unix

Closes str4d/rage#374.

rage/CHANGELOG.md

@@ -12,6 +12,10 @@ to 1.0.0 are beta releases.
 ### Added
 - Partial French translation!
 
+### Fixed
+- [Unix] Files can now be encrypted with `rage --passphrase` when piped over
+  stdin, without requiring an explicit `-` argument as `INPUT`.
+
 ## [0.10.0] - 2024-02-04
 ### Added
 - Russian translation!

rage/src/bin/rage/error.rs

@@ -23,7 +23,10 @@ macro_rules! wlnfl {
 
 pub(crate) enum EncryptError {
     Age(age::EncryptError),
-    BrokenPipe { is_stdout: bool, source: io::Error },
+    BrokenPipe {
+        is_stdout: bool,
+        source: io::Error,
+    },
     IdentityRead(age::cli_common::ReadError),
     Io(io::Error),
     MissingRecipients,
@@ -31,6 +34,7 @@ pub(crate) enum EncryptError {
     MixedRecipientAndPassphrase,
     MixedRecipientsFileAndPassphrase,
     PassphraseTimedOut,
+    #[cfg(not(unix))]
     PassphraseWithoutFileArgument,
     PluginNameFlag,
 }
@@ -84,6 +88,7 @@ impl fmt::Display for EncryptError {
                 wfl!(f, "err-enc-mixed-recipients-file-passphrase")
             }
             EncryptError::PassphraseTimedOut => wfl!(f, "err-passphrase-timed-out"),
+            #[cfg(not(unix))]
             EncryptError::PassphraseWithoutFileArgument => {
                 wfl!(f, "err-enc-passphrase-without-file")
             }

rage/src/bin/rage/main.rs

@@ -108,6 +108,7 @@ fn encrypt(opts: AgeOptions) -> Result<(), error::EncryptError> {
         (Format::Binary, file_io::OutputFormat::Binary)
     };
 
+    #[cfg(not(unix))]
     let has_file_argument = opts.input.is_some();
 
     let (input, output) = set_up_io(opts.input, opts.output, output_format)?;
@@ -134,8 +135,13 @@ fn encrypt(opts: AgeOptions) -> Result<(), error::EncryptError> {
             return Err(error::EncryptError::MixedRecipientsFileAndPassphrase);
         }
 
-        if !has_file_argument {
-            return Err(error::EncryptError::PassphraseWithoutFileArgument);
+        // The `rpassword` crate opens `/dev/tty` directly on Unix, so we don't have
+        // any conflict with stdin.
+        #[cfg(not(unix))]
+        {
+            if !has_file_argument {
+                return Err(error::EncryptError::PassphraseWithoutFileArgument);
+            }
         }
 
         match read_or_generate_passphrase() {

rage/tests/cli_tests.rs

@@ -1,4 +1,12 @@
 #[test]
 fn cli_tests() {
-    trycmd::TestCases::new().case("tests/cmd/*/*.toml");
+    let tests = trycmd::TestCases::new();
+
+    tests.case("tests/cmd/*/*.toml");
+
+    #[cfg(unix)]
+    tests.case("tests/unix/*/*.toml");
+
+    #[cfg(not(unix))]
+    tests.case("tests/windows/*/*.toml");
 }

rage/tests/unix/rage/encrypt-passphrase-without-file-argument.toml

@@ -0,0 +1,16 @@
+bin.name = "rage"
+args = "-p"
+status = "failed"
+stdin = ""
+stdout = ""
+stderr = """
+Error: Parsing Error: Error { input: "", code: Tag }
+
+[ Did rage not do what you expected? Could an error be more useful? ]
+[ Tell us: https://str4d.xyz/rage/report                            ]
+"""
+
+# We get an error from the `pinentry` crate because we've passed a real but invalid binary
+# that does not speak the pinentry protocol.
+[env.add]
+PINENTRY_PROGRAM = "true"