Improve core string type testing (#2074)

crates/libs/windows/src/core/bindings.rs

@@ -32,6 +32,7 @@ pub const FORMAT_MESSAGE_FROM_SYSTEM: u32 = 4096;
 pub const FORMAT_MESSAGE_IGNORE_INSERTS: u32 = 512;
 pub const AGILEREFERENCE_DEFAULT: i32 = 0;
 
+pub const ERROR_NO_UNICODE_TRANSLATION: u32 = 1113u32;
 pub const CLASS_E_CLASSNOTAVAILABLE: HRESULT = HRESULT(-2147221231i32);
 pub const CO_E_NOTINITIALIZED: HRESULT = HRESULT(-2147221008i32);
 pub const E_NOINTERFACE: HRESULT = HRESULT(-2147467262i32);

crates/libs/windows/src/core/error.rs

@@ -81,6 +81,18 @@ impl std::convert::From<Error> for std::io::Error {
     }
 }
 
+impl std::convert::From<std::string::FromUtf16Error> for Error {
+    fn from(_: std::string::FromUtf16Error) -> Self {
+        Self { code: HRESULT::from_win32(ERROR_NO_UNICODE_TRANSLATION), info: None }
+    }
+}
+
+impl std::convert::From<std::string::FromUtf8Error> for Error {
+    fn from(_: std::string::FromUtf8Error) -> Self {
+        Self { code: HRESULT::from_win32(ERROR_NO_UNICODE_TRANSLATION), info: None }
+    }
+}
+
 // Unfortunately this is needed to make types line up. The Rust type system does
 // not know the `Infallible` can never be constructed. This code needs to be here
 // to satesify the type checker but it will never be run. Once `!` is stabilizied

crates/tests/core/tests/pcstr.rs

@@ -0,0 +1,17 @@
+use windows::{core::*, Win32::Foundation::*};
+
+#[test]
+fn test() -> Result<()> {
+    let p: PCSTR = s!("hello");
+    let s: String = unsafe { p.to_string()? };
+    assert_eq!("hello", s);
+    assert_eq!("hello", format!("{}", unsafe { p.display() }));
+
+    let invalid = &[0xc0, 0x80];
+    let p = PCSTR::from_raw(invalid.as_ptr());
+    let e: Error = unsafe { p.to_string().unwrap_err().into() };
+    assert_eq!(e.code(), ERROR_NO_UNICODE_TRANSLATION.into());
+    assert_eq!(e.message(), "No mapping for the Unicode character exists in the target multi-byte code page.");
+
+    Ok(())
+}

crates/tests/core/tests/pcwstr.rs

@@ -0,0 +1,18 @@
+use windows::{core::*, Win32::Foundation::*};
+
+#[test]
+fn test() -> Result<()> {
+    // `w!` returns a `&HSTRING` so `into()` is needed to convert it to a `PCWSTR`
+    let p: PCWSTR = w!("hello").into();
+    let s: String = unsafe { p.to_string()? };
+    assert_eq!("hello", s);
+    assert_eq!("hello", format!("{}", unsafe { p.display() }));
+
+    let invalid = &[0xD834, 0xDD1E, 0x006d, 0x0075, 0xD800, 0x0069, 0x0063];
+    let p = PCWSTR::from_raw(invalid.as_ptr());
+    let e: Error = unsafe { p.to_string().unwrap_err().into() };
+    assert_eq!(e.code(), ERROR_NO_UNICODE_TRANSLATION.into());
+    assert_eq!(e.message(), "No mapping for the Unicode character exists in the target multi-byte code page.");
+
+    Ok(())
+}

crates/tests/core/tests/pstr.rs

@@ -0,0 +1,17 @@
+use windows::{core::*, Win32::Foundation::*};
+
+#[test]
+fn test() -> Result<()> {
+    let p = PSTR::from_raw(s!("hello").as_ptr() as *mut _);
+    let s: String = unsafe { p.to_string()? };
+    assert_eq!("hello", s);
+    assert_eq!("hello", format!("{}", unsafe { p.display() }));
+
+    let invalid = &mut [0xc0, 0x80];
+    let p = PSTR::from_raw(invalid.as_mut_ptr());
+    let e: Error = unsafe { p.to_string().unwrap_err().into() };
+    assert_eq!(e.code(), ERROR_NO_UNICODE_TRANSLATION.into());
+    assert_eq!(e.message(), "No mapping for the Unicode character exists in the target multi-byte code page.");
+
+    Ok(())
+}

crates/tests/core/tests/pwstr.rs

@@ -0,0 +1,17 @@
+use windows::{core::*, Win32::Foundation::*};
+
+#[test]
+fn test() -> Result<()> {
+    let p = PWSTR::from_raw(w!("hello").as_ptr() as *mut _);
+    let s: String = unsafe { p.to_string()? };
+    assert_eq!("hello", s);
+    assert_eq!("hello", format!("{}", unsafe { p.display() }));
+
+    let invalid = &mut [0xD834, 0xDD1E, 0x006d, 0x0075, 0xD800, 0x0069, 0x0063];
+    let p = PWSTR::from_raw(invalid.as_mut_ptr());
+    let e: Error = unsafe { p.to_string().unwrap_err().into() };
+    assert_eq!(e.code(), ERROR_NO_UNICODE_TRANSLATION.into());
+    assert_eq!(e.message(), "No mapping for the Unicode character exists in the target multi-byte code page.");
+
+    Ok(())
+}