Added property testing for encoding round-tripping.

Also fixed a bug in the utf16 encoders/decoders.

Cargo.lock

@@ -30,6 +30,37 @@ dependencies = [
  "unicode-segmentation 1.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "bit-set"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-vec 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "bit-vec"
+version = "0.5.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "bitflags"
+version = "1.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "byteorder"
+version = "1.2.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "cloudabi"
+version = "0.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "docopt"
 version = "0.8.3"
@@ -42,6 +73,25 @@ dependencies = [
  "strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "fnv"
+version = "1.0.6"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "fuchsia-zircon"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon-sys 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "fuchsia-zircon-sys"
+version = "0.3.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "lazy_static"
 version = "1.0.2"
@@ -60,6 +110,11 @@ dependencies = [
  "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "num-traits"
+version = "0.2.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "proc-macro2"
 version = "0.4.9"
@@ -68,6 +123,28 @@ dependencies = [
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "proptest"
+version = "0.8.4"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "bit-set 0.5.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "bitflags 1.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "byteorder 1.2.4 (registry+https://github.com/rust-lang/crates.io-index)",
+ "lazy_static 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "num-traits 0.2.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "regex-syntax 0.6.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rusty-fork 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "quick-error"
+version = "1.2.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "quote"
 version = "0.6.4"
@@ -76,6 +153,23 @@ dependencies = [
  "proc-macro2 0.4.9 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rand"
+version = "0.5.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "cloudabi 0.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "fuchsia-zircon 0.3.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand_core 0.2.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "rand_core"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
 [[package]]
 name = "redox_syscall"
 version = "0.1.40"
@@ -109,6 +203,22 @@ dependencies = [
  "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "regex-syntax"
+version = "0.6.2"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "remove_dir_all"
+version = "0.5.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "ropey"
 version = "0.8.4"
@@ -117,6 +227,17 @@ dependencies = [
  "smallvec 0.6.3 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "rusty-fork"
+version = "0.2.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "fnv 1.0.6 (registry+https://github.com/rust-lang/crates.io-index)",
+ "quick-error 1.2.2 (registry+https://github.com/rust-lang/crates.io-index)",
+ "tempfile 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)",
+ "wait-timeout 0.1.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "serde"
 version = "1.0.70"
@@ -155,6 +276,18 @@ dependencies = [
  "unicode-xid 0.1.0 (registry+https://github.com/rust-lang/crates.io-index)",
 ]
 
+[[package]]
+name = "tempfile"
+version = "3.0.3"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
+ "rand 0.5.5 (registry+https://github.com/rust-lang/crates.io-index)",
+ "redox_syscall 0.1.40 (registry+https://github.com/rust-lang/crates.io-index)",
+ "remove_dir_all 0.5.1 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
 [[package]]
 name = "termion"
 version = "1.5.1"
@@ -168,6 +301,9 @@ dependencies = [
 [[package]]
 name = "text_encoding"
 version = "0.1.0"
+dependencies = [
+ "proptest 0.8.4 (registry+https://github.com/rust-lang/crates.io-index)",
+]
 
 [[package]]
 name = "thread_local"
@@ -216,24 +352,68 @@ name = "void"
 version = "1.0.2"
 source = "registry+https://github.com/rust-lang/crates.io-index"
 
+[[package]]
+name = "wait-timeout"
+version = "0.1.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "libc 0.2.42 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi"
+version = "0.3.5"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+dependencies = [
+ "winapi-i686-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+ "winapi-x86_64-pc-windows-gnu 0.4.0 (registry+https://github.com/rust-lang/crates.io-index)",
+]
+
+[[package]]
+name = "winapi-i686-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
+[[package]]
+name = "winapi-x86_64-pc-windows-gnu"
+version = "0.4.0"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+
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 "checksum ropey 0.8.4 (git+https://github.com/cessen/ropey)" = "<none>"
+"checksum rusty-fork 0.2.0 (registry+https://github.com/rust-lang/crates.io-index)" = "ea98d8d2644fd8b4946a2be90e8c6dc52b652e03079c46e134d9815062b9082d"
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 "checksum strsim 0.6.0 (registry+https://github.com/rust-lang/crates.io-index)" = "b4d15c810519a91cf877e7e36e63fe068815c678181439f2f29e2562147c3694"
 "checksum syn 0.14.5 (registry+https://github.com/rust-lang/crates.io-index)" = "4bad7abdf6633f07c7046b90484f1d9dc055eca39f8c991177b1046ce61dba9a"
+"checksum tempfile 3.0.3 (registry+https://github.com/rust-lang/crates.io-index)" = "c4b103c6d08d323b92ff42c8ce62abcd83ca8efa7fd5bf7927efefec75f58c76"
 "checksum termion 1.5.1 (registry+https://github.com/rust-lang/crates.io-index)" = "689a3bdfaab439fd92bc87df5c4c78417d3cbe537487274e9b0b2dce76e92096"
 "checksum thread_local 0.3.5 (registry+https://github.com/rust-lang/crates.io-index)" = "279ef31c19ededf577bfd12dfae728040a21f635b06a24cd670ff510edd38963"
 "checksum ucd-util 0.1.1 (registry+https://github.com/rust-lang/crates.io-index)" = "fd2be2d6639d0f8fe6cdda291ad456e23629558d466e2789d2c3e9892bda285d"
@@ -243,3 +423,7 @@ source = "registry+https://github.com/rust-lang/crates.io-index"
 "checksum unreachable 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "382810877fe448991dfc7f0dd6e3ae5d58088fd0ea5e35189655f84e6814fa56"
 "checksum utf8-ranges 1.0.0 (registry+https://github.com/rust-lang/crates.io-index)" = "662fab6525a98beff2921d7f61a39e7d59e0b425ebc7d0d9e66d316e55124122"
 "checksum void 1.0.2 (registry+https://github.com/rust-lang/crates.io-index)" = "6a02e4885ed3bc0f2de90ea6dd45ebcbb66dacffe03547fadbb0eeae2770887d"
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sub_crates/text_encoding/Cargo.toml

@@ -6,4 +6,7 @@ license = "MIT"
 
 [lib]
 name = "text_encoding"
-path = "src/lib.rs"
+path = "src/lib.rs"
+
+[dev-dependencies]
+proptest = "0.8"

sub_crates/text_encoding/src/utf16_be.rs

@@ -113,7 +113,7 @@ pub fn decode_to_utf8<'a>(input: &[u8], output: &'a mut [u8]) -> DecodeResult<'a
                 }
                 let bytes_2 = itr.next().unwrap();
                 let code_2 = from_big_endian([bytes_2[0], bytes_2[1]]);
-                if !(code_2 & 0xFC00) == 0xDC00 {
+                if (code_2 & 0xFC00) != 0xDC00 {
                     // Error: second half is not valid surrogate.
                     return Err(DecodeError {
                         error_range: (input_i, input_i + 2),

sub_crates/text_encoding/src/utf16_le.rs

@@ -113,7 +113,7 @@ pub fn decode_to_utf8<'a>(input: &[u8], output: &'a mut [u8]) -> DecodeResult<'a
                 }
                 let bytes_2 = itr.next().unwrap();
                 let code_2 = from_little_endian([bytes_2[0], bytes_2[1]]);
-                if !(code_2 & 0xFC00) == 0xDC00 {
+                if (code_2 & 0xFC00) != 0xDC00 {
                     // Error: second half is not valid surrogate.
                     return Err(DecodeError {
                         error_range: (input_i, input_i + 2),

sub_crates/text_encoding/tests/property_tests.rs

@@ -0,0 +1,175 @@
+#[macro_use]
+extern crate proptest;
+extern crate text_encoding;
+
+use proptest::collection::vec;
+use proptest::test_runner::Config;
+use text_encoding::{decode_to_utf8, encode_from_utf8, Encoding};
+
+proptest! {
+    #![proptest_config(Config::with_cases(512))]
+
+    #[test]
+    fn pt_utf8_roundtrip(ref text in "\\PC*\\PC*\\PC*") {
+        let mut buf = [0u8; 32];
+        let mut utf8_encoded: Vec<u8> = Vec::new();
+        let mut utf8 = String::new();
+
+        // Encode to utf8
+        let mut tmp = &text[..];
+        while !tmp.is_empty() {
+            if let Ok((n, encoded)) = encode_from_utf8(Encoding::Utf8, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8_encoded.extend_from_slice(encoded);
+            } else {
+                panic!("Error when encoding.");
+            }
+        }
+
+        // Decode back from utf8
+        let mut tmp = &utf8_encoded[..];
+        while !tmp.is_empty() {
+            if let Ok((n, decoded)) = decode_to_utf8(Encoding::Utf8, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8.extend(decoded.chars());
+            } else {
+                panic!("Error when decoding.");
+            }
+        }
+
+        assert_eq!(&text[..], &utf8[..]);
+        assert_eq!(text.as_bytes(), &utf8_encoded[..]);
+        assert_eq!(utf8.as_bytes(), &utf8_encoded[..]);
+    }
+
+    #[test]
+    fn pt_utf16be_roundtrip(ref text in "\\PC*\\PC*\\PC*") {
+        let mut buf = [0u8; 32];
+        let mut utf16: Vec<u8> = Vec::new();
+        let mut utf8 = String::new();
+
+        // Encode to utf16 big endian
+        let mut tmp = &text[..];
+        while !tmp.is_empty() {
+            if let Ok((n, encoded)) = encode_from_utf8(Encoding::Utf16BE, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf16.extend_from_slice(encoded);
+            } else {
+                panic!("Error when encoding.");
+            }
+        }
+
+        // Decode back from utf16 big endian
+        let mut tmp = &utf16[..];
+        while !tmp.is_empty() {
+            if let Ok((n, decoded)) = decode_to_utf8(Encoding::Utf16BE, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8.extend(decoded.chars());
+            } else {
+                panic!("Error when decoding.");
+            }
+        }
+
+        assert_eq!(&text[..], &utf8[..]);
+    }
+
+    #[test]
+    fn pt_utf16le_roundtrip(ref text in "\\PC*\\PC*\\PC*") {
+        let mut buf = [0u8; 32];
+        let mut utf16: Vec<u8> = Vec::new();
+        let mut utf8 = String::new();
+
+        // Encode to utf16 little endian
+        let mut tmp = &text[..];
+        while !tmp.is_empty() {
+            if let Ok((n, encoded)) = encode_from_utf8(Encoding::Utf16LE, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf16.extend_from_slice(encoded);
+            } else {
+                panic!("Error when encoding.");
+            }
+        }
+
+        // Decode back from utf16 big endian
+        let mut tmp = &utf16[..];
+        while !tmp.is_empty() {
+            if let Ok((n, decoded)) = decode_to_utf8(Encoding::Utf16LE, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8.extend(decoded.chars());
+            } else {
+                panic!("Error when decoding.");
+            }
+        }
+
+        assert_eq!(&text[..], &utf8[..]);
+    }
+
+    #[test]
+    fn pt_latin1_roundtrip(ref data in vec(0u8..=255, 0..1000)) {
+        let mut buf = [0u8; 32];
+        let mut utf8 = String::new();
+        let mut latin1: Vec<u8> = Vec::new();
+
+        // Decode from latin1 to utf8
+        let mut tmp = &data[..];
+        while !tmp.is_empty() {
+            if let Ok((n, decoded)) = decode_to_utf8(Encoding::Latin1, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8.extend(decoded.chars());
+            } else {
+                panic!("Error when decoding.");
+            }
+        }
+
+        // Encode to from utf8 back to latin1
+        let mut tmp = &utf8[..];
+        while !tmp.is_empty() {
+            if let Ok((n, encoded)) = encode_from_utf8(Encoding::Latin1, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                latin1.extend_from_slice(encoded);
+            } else {
+                panic!("Error when encoding.");
+            }
+        }
+
+        assert_eq!(&data[..], &latin1[..]);
+    }
+
+    #[test]
+    fn pt_windows1252_roundtrip(mut data in vec(0u8..=255, 0..1000)) {
+        let mut buf = [0u8; 32];
+        let mut utf8 = String::new();
+        let mut w1252: Vec<u8> = Vec::new();
+
+        // Eliminate undefined bytes in input.
+        for b in data.iter_mut() {
+            if *b == 0x81 || *b == 0x8D || *b == 0x8F || *b == 0x90 || *b == 0x9D {
+                *b = 0;
+            }
+        }
+
+        // Decode from windows-1252 to utf8
+        let mut tmp = &data[..];
+        while !tmp.is_empty() {
+            if let Ok((n, decoded)) = decode_to_utf8(Encoding::Windows1252, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                utf8.extend(decoded.chars());
+            } else {
+                panic!("Error when decoding.");
+            }
+        }
+
+        // Encode to from utf8 back to w1252
+        let mut tmp = &utf8[..];
+        while !tmp.is_empty() {
+            if let Ok((n, encoded)) = encode_from_utf8(Encoding::Windows1252, tmp, &mut buf) {
+                tmp = &tmp[n..];
+                w1252.extend_from_slice(encoded);
+            } else {
+                panic!("Error when encoding.");
+            }
+        }
+
+        assert_eq!(&data[..], &w1252[..]);
+    }
+}