Merge #1656

1656: Added tests for cargo macros, fixes #1478 r=pksunkara a=pksunkara

When you approve this PR, instead of merging it, please comment "bors r+". I want to test the bors workflow.

Co-authored-by: Pavan Kumar Sunkara <pavan.sss1991@gmail.com>

CHANGELOG.md

@@ -2,10 +2,10 @@
 
 #### Minimum Required Rust
 
-* As of this release, `clap` requires `rustc 1.33.0` or greater.
+* As of this release, `clap` requires `rustc 1.36.0` or greater.
 
 <a name="v2.29.2"></a>
-### v2.29.2 (2018-01-16)
+## v2.29.2 (2018-01-16)
 
 
 #### Features

tests/app_from_crate.rs

@@ -0,0 +1,26 @@
+use clap::{app_from_crate, ErrorKind};
+
+static EVERYTHING: &str = "clap {{version}}
+Kevin K. <kbknapp@gmail.com>
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    clap
+
+FLAGS:
+    -h, --help       Prints help information
+    -V, --version    Prints version information
+";
+
+#[test]
+fn app_from_crate() {
+    let res = app_from_crate!().try_get_matches_from(vec!["clap", "--help"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::HelpDisplayed);
+    assert_eq!(
+        err.message,
+        EVERYTHING.replace("{{version}}", env!("CARGO_PKG_VERSION"))
+    );
+}

tests/cargo.rs

@@ -0,0 +1,71 @@
+use clap::{crate_authors, crate_description, crate_name, crate_version, App, ErrorKind};
+
+static DESCRIPTION_ONLY: &str = "prog 1
+A simple to use, efficient, and full-featured Command Line Argument Parser
+
+USAGE:
+    prog
+
+FLAGS:
+    -h, --help       Prints help information
+    -V, --version    Prints version information
+";
+
+static AUTHORS_ONLY: &str = "prog 1
+Kevin K. <kbknapp@gmail.com>
+
+USAGE:
+    prog
+
+FLAGS:
+    -h, --help       Prints help information
+    -V, --version    Prints version information
+";
+
+#[test]
+fn crate_version() {
+    let res = App::new("prog")
+        .version(crate_version!())
+        .try_get_matches_from(vec!["prog", "--version"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::VersionDisplayed);
+    assert_eq!(err.message, format!("prog {}", env!("CARGO_PKG_VERSION")));
+}
+
+#[test]
+fn crate_description() {
+    let res = App::new("prog")
+        .version("1")
+        .about(crate_description!())
+        .try_get_matches_from(vec!["prog", "--help"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::HelpDisplayed);
+    assert_eq!(err.message, DESCRIPTION_ONLY);
+}
+
+#[test]
+fn crate_authors() {
+    let res = App::new("prog")
+        .version("1")
+        .author(crate_authors!())
+        .try_get_matches_from(vec!["prog", "--help"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::HelpDisplayed);
+    assert_eq!(err.message, AUTHORS_ONLY);
+}
+
+#[test]
+fn crate_name() {
+    let res = App::new(crate_name!()).try_get_matches_from(vec!["clap", "--version"]);
+
+    assert!(res.is_err());
+    let err = res.unwrap_err();
+    assert_eq!(err.kind, ErrorKind::VersionDisplayed);
+    assert_eq!(err.message, "clap ");
+}