feat(clog): auto increment version with --major, --minor, or --patch

Only compatible with semver at the moment

Closes #19

Cargo.toml

@@ -13,3 +13,4 @@ description = "A conventional changelog for the rest of us"
 regex = "*"
 time = "*"
 clap = "*"
+semver = "*"

src/git.rs

@@ -3,6 +3,8 @@ use common:: { LogEntry };
 use common::CommitType;
 use std::borrow::ToOwned;
 
+use semver; 
+
 #[derive(Debug)]
 pub struct LogReaderConfig {
     pub grep: String,
@@ -16,17 +18,27 @@ pub fn get_latest_tag () -> String {
             .arg("rev-list")
             .arg("--tags")
             .arg("--max-count=1")
-            .output().unwrap_or_else(|e| panic!("Failed to run git rev-list with error: {}",e));
+            .output().unwrap_or_else(|e| panic!("Failed to run 'git rev-list' with error: {}",e));
     let buf = String::from_utf8_lossy(&output.stdout);
 
     buf.trim_matches('\n').to_owned()
 }
 
+pub fn get_latest_tag_ver () -> Result<semver::Version, semver::ParseError> {
+    let output = Command::new("git")
+            .arg("describe")
+            .arg("--tags")
+            .arg("--abbrev=0")
+            .output().unwrap_or_else(|e| panic!("Failed to run 'git describe' with error: {}",e));
+
+    semver::Version::parse(&String::from_utf8_lossy(&output.stdout)[..])
+}
+
 pub fn get_last_commit () -> String {
     let output = Command::new("git")
             .arg("rev-parse")
             .arg("HEAD")
-            .output().unwrap_or_else(|e| panic!("Failed to run git rev-parse with error: {}", e));
+            .output().unwrap_or_else(|e| panic!("Failed to run 'git rev-parse' with error: {}", e));
 
     String::from_utf8_lossy(&output.stdout).into_owned()
 }
@@ -44,7 +56,7 @@ pub fn get_log_entries (config:LogReaderConfig) -> Vec<LogEntry>{
             .arg(&format!("--grep={}",config.grep))
             .arg(&format!("--format={}", "%H%n%s%n%b%n==END=="))
             .arg(&range)
-            .output().unwrap_or_else(|e| panic!("Failed to run git log with error: {}", e));
+            .output().unwrap_or_else(|e| panic!("Failed to run 'git log' with error: {}", e));
 
     String::from_utf8_lossy(&output.stdout)
             .split("\n==END==\n")

src/main.rs

@@ -2,6 +2,7 @@
 
 extern crate regex;
 extern crate time;
+extern crate semver;
 
 #[macro_use]
 extern crate clap;
@@ -32,14 +33,18 @@ fn main () {
         .version(&crate_version!()[..])
         .about("a conventional changelog for the rest of us")
         .args_from_usage("-r --repository=[repository]  'e.g. https://github.com/thoughtram/clog'
-                          --setversion=[setversion]     'e.g. 1.0.1'
                           --from=[from]                 'e.g. 12a8546'
+                          --major                       'Increment major version by one (Sets minor and patch to 0)'
+                          --minor                       'Increment minor version by one (Sets patch to 0)'
+                          --patch                       'Increment patch version by one'
                           --subtitle=[subtitle]         'e.g. crazy-release-title'
                           --to=[to]                     'e.g. 8057684 (Defaults to HEAD when omitted)'")
         // Because --from-latest-tag can't be used with --from, we add it seperately so we can
         // specify a .mutually_excludes()
         .arg(Arg::from_usage("--from-latest-tag 'use latest tag as start (instead of --from)'")
                 .mutually_excludes("from"))
+        .arg(Arg::from_usage("--setversion=[setversion]     'e.g. 1.0.1'")
+                .mutually_excludes_all(vec!["major", "minor", "patch"]))
         .get_matches();
 
     let start_nsec = time::get_time().nsec;
@@ -51,6 +56,34 @@ fn main () {
         to: matches.value_of("to").unwrap_or("").to_owned()
     };
 
+    // compute version early, so we can exit on error
+    let version =  {
+        // less typing later...
+        let (major, minor, patch) = (matches.is_present("major"), matches.is_present("minor"), matches.is_present("patch"));
+        if matches.is_present("setversion") {
+            matches.value_of("setversion").unwrap().to_owned()
+        } else if major || minor || patch {
+            match git::get_latest_tag_ver() {
+                Ok(ref mut v) => {
+                    // if-else may be quicker, but it's longer mentally, and this isn't slow
+                    match (major, minor, patch) {
+                        (true,_,_) => { v.major += 1; v.minor = 0; v.patch = 0; },
+                        (_,true,_) => { v.minor += 1; v.patch = 0; },
+                        (_,_,true) => { v.patch += 1; },
+                        _          => unreachable!()
+                    }
+                    format!("{}", v)
+                },
+                Err(e) => {
+                    println!("Error parsing latest version: {}\nTry setting the version manually with --setversion=[version]", e );
+                    std::process::exit(1);
+                }
+            }
+        } else {           
+            format_util::get_short_hash(&git::get_last_commit()[..]).to_owned()
+        }
+    };
+
     let commits = git::get_log_entries(log_reader_config);
 
     let sections = section_builder::build_sections(commits.clone());
@@ -62,11 +95,7 @@ fn main () {
     let mut file = File::create(&Path::new("changelog.md")).ok().unwrap();
     let mut writer = LogWriter::new(&mut file, LogWriterOptions {
         repository_link: matches.value_of("repository").unwrap_or(""),
-        version: if matches.is_present("setversion") {
-                    matches.value_of("setversion").unwrap().to_owned()
-                } else {
-                    format_util::get_short_hash(&git::get_last_commit()[..]).to_owned()
-                },
+        version: version,
         subtitle: matches.value_of("subtitle").unwrap_or("").to_owned()
     });