rust/utils: move common code to a function

Signed-off-by: Rafael Fonseca <r4f4rfs@gmail.com>

rust/src/lockfile.rs

@@ -17,40 +17,12 @@ use std::io;
 
 use crate::utils;
 
-/// Parse a JSON lockfile definition.
-fn lockfile_parse_stream<R: io::Read>(
-    fmt: utils::InputFormat,
-    input: &mut R,
-) -> Fallible<LockfileConfig> {
-    let lockfile: LockfileConfig = match fmt {
-        utils::InputFormat::JSON => {
-            let lf: LockfileConfig = serde_json::from_reader(input).map_err(|e| {
-                io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    format!("serde-json: {}", e.to_string()),
-                )
-            })?;
-            lf
-        }
-        utils::InputFormat::YAML => {
-            let lf: LockfileConfig = serde_yaml::from_reader(input).map_err(|e| {
-                io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    format!("serde-yaml: {}", e.to_string()),
-                )
-            })?;
-            lf
-        }
-    };
-    Ok(lockfile)
-}
-
 /// Given a lockfile filename, parse it
 fn lockfile_parse<P: AsRef<Path>>(filename: P,) -> Fallible<LockfileConfig> {
     let filename = filename.as_ref();
     let fmt = utils::InputFormat::detect_from_filename(filename)?;
     let mut f = io::BufReader::new(utils::open_file(filename)?);
-    let lf = lockfile_parse_stream(fmt, &mut f).map_err(|e| {
+    let lf = utils::parse_stream(&fmt, &mut f).map_err(|e| {
         io::Error::new(
             io::ErrorKind::InvalidInput,
             format!("Parsing {}: {}", filename.to_string_lossy(), e.to_string()),
@@ -142,7 +114,7 @@ mod tests {
     #[test]
     fn basic_valid() {
         let mut input = io::BufReader::new(VALID_PRELUDE_JS.as_bytes());
-        let lockfile = lockfile_parse_stream(utils::InputFormat::JSON, &mut input).unwrap();
+        let lockfile: LockfileConfig = utils::parse_stream(&utils::InputFormat::JSON, &mut input).unwrap();
         assert!(lockfile.packages.len() == 2);
     }
 
@@ -160,11 +132,11 @@ mod tests {
     #[test]
     fn basic_valid_override() {
         let mut base_input = io::BufReader::new(VALID_PRELUDE_JS.as_bytes());
-        let mut base_lockfile = lockfile_parse_stream(utils::InputFormat::JSON, &mut base_input).unwrap();
+        let mut base_lockfile: LockfileConfig = utils::parse_stream(&utils::InputFormat::JSON, &mut base_input).unwrap();
         assert!(base_lockfile.packages.len() == 2);
 
         let mut override_input = io::BufReader::new(OVERRIDE_JS.as_bytes());
-        let override_lockfile = lockfile_parse_stream(utils::InputFormat::JSON, &mut override_input).unwrap();
+        let override_lockfile: LockfileConfig = utils::parse_stream(&utils::InputFormat::JSON, &mut override_input).unwrap();
         assert!(override_lockfile.packages.len() == 1);
 
         base_lockfile.merge(override_lockfile);
@@ -176,7 +148,7 @@ mod tests {
     #[test]
     fn test_invalid() {
         let mut input = io::BufReader::new(INVALID_PRELUDE_JS.as_bytes());
-        match lockfile_parse_stream(utils::InputFormat::JSON, &mut input) {
+        match utils::parse_stream::<LockfileConfig, _>(&utils::InputFormat::JSON, &mut input) {
             Err(ref e) => match e.downcast_ref::<io::Error>() {
                 Some(ref ioe) if ioe.kind() == io::ErrorKind::InvalidInput => {}
                 _ => panic!("Expected invalid lockfile, not {}", e.to_string()),

rust/src/treefile.rs

@@ -13,7 +13,6 @@ use failure::{Fallible, bail};
 use openat;
 use serde_derive::{Deserialize, Serialize};
 use serde_json;
-use serde_yaml;
 use std::collections::{HashMap, BTreeMap};
 use std::io::prelude::*;
 use std::path::Path;
@@ -63,26 +62,7 @@ fn treefile_parse_stream<R: io::Read>(
     input: &mut R,
     basearch: Option<&str>,
 ) -> Fallible<TreeComposeConfig> {
-    let mut treefile: TreeComposeConfig = match fmt {
+    let mut treefile: TreeComposeConfig = utils::parse_stream(&fmt, input)?;
-        utils::InputFormat::YAML => {
-            let tf: TreeComposeConfig = serde_yaml::from_reader(input).map_err(|e| {
-                io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    format!("serde-yaml: {}", e.to_string()),
-                )
-            })?;
-            tf
-        }
-        utils::InputFormat::JSON => {
-            let tf: TreeComposeConfig = serde_json::from_reader(input).map_err(|e| {
-                io::Error::new(
-                    io::ErrorKind::InvalidInput,
-                    format!("serde-json: {}", e.to_string()),
-                )
-            })?;
-            tf
-        }
-    };
 
     treefile.basearch = match (treefile.basearch, basearch) {
         (Some(treearch), Some(arch)) => {

rust/src/utils.rs

@@ -14,6 +14,9 @@ use tempfile;
 
 use curl::easy::Easy;
 
+use serde_json;
+use serde_yaml;
+
 #[derive(PartialEq)]
 /// Supported config serialization used by treefile and lockfile
 pub enum InputFormat {
@@ -36,6 +39,34 @@ impl InputFormat {
     }
 }
 
+/// Given a lockfile/treefile config definition, parse it
+pub fn parse_stream<T, R: io::Read>(fmt: &InputFormat, input: &mut R) -> Fallible<T>
+where
+    T: serde::de::DeserializeOwned
+{
+    let parsed: T = match fmt {
+        InputFormat::JSON => {
+            let pf: T = serde_json::from_reader(input).map_err(|e| {
+                io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    format!("serde-json: {}", e.to_string()),
+                )
+            })?;
+            pf
+        }
+        InputFormat::YAML => {
+            let pf: T = serde_yaml::from_reader(input).map_err(|e| {
+                io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    format!("serde-yaml: {}", e.to_string()),
+                )
+            })?;
+            pf
+        }
+    };
+    Ok(parsed)
+}
+
 fn download_url_to_tmpfile(url: &str) -> Fallible<fs::File> {
     let mut tmpf = tempfile::tempfile()?;
     {