fmt trait tests

test_suite/Cargo.toml

@@ -37,3 +37,8 @@ edition = "2018"
 name = "bitflags-test-no-implicit-prelude-2018"
 path = "tests/no_implicit_prelude_2018.rs"
 edition = "2018"
+
+[[test]]
+name = "bitflags-formatting"
+path = "tests/formatting.rs"
+edition = "2018"

test_suite/tests/formatting.rs

@@ -0,0 +1,74 @@
+use enumflags2_derive::EnumFlags;
+
+include!("../common.rs");
+
+#[test]
+fn debug_format() {
+    use enumflags2::BitFlags;
+
+    // Assert that our Debug output format meets expectations
+
+    assert_eq!(
+        format!("{:?}", BitFlags::<Test>::all()),
+        "BitFlags<Test>(0b1111, A | B | C | D)"
+    );
+
+    assert_eq!(
+        format!("{:?}", BitFlags::<Test>::empty()),
+        "BitFlags<Test>(0b0)"
+    );
+
+    assert_eq!(
+        format!("{:04x?}", BitFlags::<Test>::all()),
+        "BitFlags<Test>(0x0f, A | B | C | D)"
+    );
+
+    assert_eq!(
+        format!("{:04X?}", BitFlags::<Test>::all()),
+        "BitFlags<Test>(0x0F, A | B | C | D)"
+    );
+
+    // Also check alternate struct formatting
+
+    assert_eq!(
+        format!("{:#010?}", BitFlags::<Test>::all()),
+"BitFlags<Test> {
+    bits: 0b00001111,
+    flags: A | B | C | D,
+}"
+    );
+
+    assert_eq!(
+        format!("{:#?}", BitFlags::<Test>::empty()),
+"BitFlags<Test> {
+    bits: 0b0,
+}"
+    );
+}
+
+#[test]
+fn format() {
+    use enumflags2::BitFlags;
+
+    // Assert BitFlags<T> impls fmt::{Binary, Octal, LowerHex, UpperHex}
+
+    assert_eq!(
+        format!("{:b}", BitFlags::<Test>::all()),
+        "1111"
+    );
+
+    assert_eq!(
+        format!("{:o}", BitFlags::<Test>::all()),
+        "17"
+    );
+
+    assert_eq!(
+        format!("{:x}", BitFlags::<Test>::all()),
+        "f"
+    );
+
+    assert_eq!(
+        format!("{:#04X}", BitFlags::<Test>::all()),
+        "0x0F"
+    );
+}