Add YAML support to CLI (#3)

* Add yaml support

* Update README

Cargo.toml

@@ -14,6 +14,7 @@ structopt = "0.2.15"
 serde = "1.0.90"
 toml = "0.5.0"
 serde_json = "1.0.39"
+serde_yaml = "0.8.8"
 
 [[bin]]
 name = "tera"

README.md

@@ -8,8 +8,9 @@ Tera CLI for one-off template interpolation from context file / env vars.
 
 The following context formats are supported:
 
-- TOML context file
-- JSON context file
+- JSON context file (`--json .` defaults to `.tera.json`)
+- TOML context file (`--toml .` defaults to `.tera.toml`)
+- YAML context file (`--yaml .` defaults to `.tera.yml`)
 - Environment variables
 
 ## Simple Examples

src/main.rs

@@ -1,4 +1,5 @@
 use serde_json;
+use serde_yaml;
 use std::{
     collections::HashMap,
     env,
@@ -55,6 +56,11 @@ struct ContextFormat {
     #[structopt(name = "json", long, group = "format", parse(from_os_str))]
     json: Option<PathBuf>,
 
+    /// YAML file path to read context values.
+    /// "." to indicate reading from default ".tera.yml"
+    #[structopt(name = "yaml", long, group = "format", parse(from_os_str))]
+    yaml: Option<PathBuf>,
+
     /// Use env vars as the context instead
     #[structopt(name = "env", long, group = "format")]
     env: bool,
@@ -117,6 +123,14 @@ fn read_context(conf: &Args) -> CliResult<Context> {
         let mut context = Context::new();
         context.insert(&conf.root_key, &value);
         Ok(context)
+    } else if let Some(ref path) = conf.context.yaml {
+        // YAML
+        let path = get_config_path(path, ".yml");
+        let value: serde_yaml::Value =
+            serde_yaml::from_str(&fs::read_to_string(&path)?)?;
+        let mut context = Context::new();
+        context.insert(&conf.root_key, &value);
+        Ok(context)
     } else if conf.context.env {
         let env_vars = env::vars().collect::<HashMap<String, String>>();
         let mut context = Context::new();