feat(debug): Adding CLI for testing liquid

Note: this relies on a nightly Cargo.toml feature `required-features`.
Under stable, you will see a warning about an unsupported option and then
the build will fail due to a missing `clap` unless you specify
`--features=cli`.

.travis.yml

@@ -13,9 +13,9 @@ install:
   - export PATH=$HOME/.cargo/bin:$PATH
 
 script:
-  - cargo build
-  - cargo test
-  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (cargo clippy) fi
+  - cargo build --features=cli
+  - cargo test --features=cli
+  - if [ "$TRAVIS_RUST_VERSION" = "nightly" ]; then (cargo clippy --features=cli) fi
   - cargo fmt -- --write-mode=diff
 
 addons:

Cargo.toml

@@ -1,5 +1,4 @@
 [package]
-
 name = "liquid"
 version = "0.9.1"
 authors = ["Johann Hofmann <[email protected]>"]
@@ -13,22 +12,33 @@ license = "MIT"
 
 build = "build.rs"
 
+[[bin]]
+name = "liquid-dbg"
+required-features = ["cli"]
+test = false
+doctest = false
+bench = false
+doc = false
+
+[features]
+default = ["extra-filters"]
+cli = ["clap", "error-chain", "toml"]
+extra-filters = []
+dev = []
+
 [dependencies]
 regex = "0.2"
 lazy_static = "0.2"
 chrono = "0.3"
 unicode-segmentation = "1.1"
 
+clap = { version = "2.22.0", optional = true }
+error-chain = { version = "0.10.0", optional = true }
+toml = { version = "0.3.2", optional = true }
+
 [build-dependencies]
 skeptic = "0.9"
 
 [dev-dependencies]
 difference = "1.0"
 skeptic = "0.9"
-
-[features]
-default = ["extra-filters"]
-
-extra-filters = []
-
-dev=[]

appveyor.yml

@@ -27,7 +27,8 @@ install:
   - cargo -V
 
 test_script:
-  - cargo build --verbose
+  - cargo build --verbose --features=cli
+  - cargo test --features=cli
 
 cache:
   - C:\Users\appveyor\.cargo\registry

src/main.rs

@@ -0,0 +1,122 @@
+#[macro_use]
+extern crate clap;
+#[macro_use]
+extern crate error_chain;
+extern crate liquid;
+extern crate toml;
+
+use std::collections;
+use std::fs;
+use std::io;
+use std::io::{Write, Read};
+use std::path;
+use liquid::Renderable;
+
+macro_rules! println_stderr(
+    ($($arg:tt)*) => { {
+        let r = writeln!(&mut ::std::io::stderr(), $($arg)*);
+        r.expect("failed printing to stderr");
+    } }
+);
+
+error_chain! {
+
+    links {
+    }
+
+    foreign_links {
+        Clap(clap::Error);
+        Io(io::Error);
+        Liquid(liquid::Error);
+        Toml(toml::de::Error);
+    }
+
+    errors {
+    }
+}
+
+fn option<'a>(name: &'a str, value: &'a str) -> clap::Arg<'a, 'a> {
+    clap::Arg::with_name(name).long(name).value_name(value)
+}
+
+fn convert_value(toml_value: &toml::Value) -> Result<liquid::Value> {
+    match *toml_value {
+        toml::Value::String(ref s) => Ok(liquid::Value::Str(s.to_string())),
+        toml::Value::Integer(n) => Ok(liquid::Value::Num(n as f32)),
+        toml::Value::Float(n) => Ok(liquid::Value::Num(n as f32)),
+        toml::Value::Boolean(b) => Ok(liquid::Value::Bool(b)),
+        toml::Value::Datetime(_) => Err("Datetime's are unsupported".into()),
+        toml::Value::Array(ref a) => {
+            let liquid_array: Result<Vec<liquid::Value>> = a.iter().map(convert_value).collect();
+            let liquid_array = liquid_array?;
+            Ok(liquid::Value::Array(liquid_array))
+        }
+        toml::Value::Table(ref t) => {
+            let liquid_object: Result<collections::HashMap<String, liquid::Value>> = t.iter()
+                .map(|(k, v)| {
+                    let v = convert_value(v);
+                    match v {
+                        Ok(v) => Ok((k.to_string(), v)),
+                        Err(e) => Err(e),
+                    }
+                })
+                .collect();
+            let liquid_object = liquid_object?;
+            Ok(liquid::Value::Object(liquid_object))
+        }
+    }
+}
+
+fn build_context(path: &path::Path) -> Result<liquid::Context> {
+    let mut input = String::new();
+    let mut f = fs::File::open(path)?;
+    f.read_to_string(&mut input)?;
+    let input: toml::Value = input.parse()?;
+    let value = convert_value(&input)?;
+    let value = match value {
+        liquid::Value::Object(o) => Ok(o),
+        _ => Err("File must be a toml table"),
+    }?;
+    let data = liquid::Context::with_values(value);
+
+    Ok(data)
+}
+
+fn run() -> Result<()> {
+    let matches = clap::App::new("liquidate").version(crate_version!())
+        .author(crate_authors!())
+        .arg(option("input", "LIQUID").required(true))
+        .arg(option("output", "TXT"))
+        .arg(option("context", "TOML"))
+        .arg(option("include-root", "PATH"))
+        .get_matches_safe()?;
+
+    let mut options = liquid::LiquidOptions::default();
+    options.file_system = matches.value_of("include-root").map(path::PathBuf::from);
+
+    let mut data = matches.value_of("context")
+        .map(|s| {
+            let p = path::PathBuf::from(s);
+            build_context(p.as_path())
+        })
+        .map_or(Ok(None), |r| r.map(Some))?
+        .unwrap_or_else(liquid::Context::new);
+
+    let template_path =
+        matches.value_of("input").map(path::PathBuf::from).expect("Parameter was required");
+    let template = liquid::parse_file(template_path, options)?;
+    let output = template.render(&mut data)?.unwrap_or_else(|| "".to_string());
+    match matches.value_of("output") {
+        Some(path) => {
+            let mut out = fs::File::create(path::PathBuf::from(path))?;
+            out.write_all(output.as_bytes())?;
+        }
+        None => {
+            println!("{}", output);
+        }
+    }
+
+    Ok(())
+}
+
+quick_main!(run);