Diff null sources

Cargo.toml

@@ -51,8 +51,9 @@ comrak = "0.4"
 serde_json = "1.0"
 serde_derive = "1.0"
 diff-rs = "0.2"
-patch-rs = "0.5"
+patch-rs = "0.6"
 splitdiff-rs = "0.4"
+interdiff-rs = "0.2"
 select = "0.4"
 scl = { git = "https://github.com/foundpatterns/scl" }
 # string

src/bindings/text/diff.rs

@@ -6,6 +6,11 @@ use std::{
 use chrono::{DateTime, Local};
 use diff_rs::diff;
 
+#[cfg(target_os = "windows")]
+const NULL_SOURCE: &str = "nul";
+#[cfg(target_os = "linux")]
+const NULL_SOURCE: &str = "/dev/null";
+
 fn time_format(d: &DateTime<Local>) -> String {
     d.format("%Y-%m-%d %H:%M:%S.%f %z").to_string()
 }
@@ -53,8 +58,23 @@ pub fn init(lua: &Lua) -> crate::Result<()> {
             format!("+++ {}\t{}", &right, time_format(&mtime(&right).map_err(LuaError::external)?))
         ];
 
-        let left = read_file(&left).map_err(LuaError::external)?;
-        let right = read_file(&right).map_err(LuaError::external)?;
+        if left == NULL_SOURCE && right == NULL_SOURCE {
+            return Err(rlua::Error::external(io::Error::new(
+                io::ErrorKind::InvalidInput,
+                "Both files cannot be null"
+            )));
+        }
+
+        let left = if left != NULL_SOURCE {
+            read_file(&left).map_err(LuaError::external)?
+        } else {
+            Vec::new()
+        };
+        let right = if right != NULL_SOURCE {
+            Vec::new()
+        } else {
+            read_file(&right).map_err(LuaError::external)?
+        };
 
         let diff = diff(&left, &right, 3).map_err(LuaError::external)?;
 
@@ -69,4 +89,3 @@ pub fn init(lua: &Lua) -> crate::Result<()> {
 
     Ok(())
 }
-

src/bindings/text/interdiff.rs

@@ -0,0 +1,45 @@
+use rlua::Lua;
+
+use std::{io, fs};
+use patch_rs::{Patch, PatchProcessor};
+
+#[cfg(target_os = "windows")]
+const NULL_SOURCE: &str = "nul";
+#[cfg(target_os = "linux")]
+const NULL_SOURCE: &str = "/dev/null";
+
+pub fn init(lua: &Lua) -> crate::Result<()> {
+    let module = lua.create_table()?;
+
+    module.set(
+        "interdiff",
+        lua.create_function(|_, (patch_1, patch_2): (String, String)| {
+            if patch_1 == NULL_SOURCE && patch_2 == NULL_SOURCE {
+                return Err(rlua::Error::external(io::Error::new(
+                    io::ErrorKind::InvalidInput,
+                    "Both patches cannot be null"
+                )));
+            }
+
+            let patch_1 = if patch_1 != NULL_SOURCE {
+                let patch_1 = fs::read_to_string(patch_1).map_err(rlua::Error::external)?;
+                PatchProcessor::convert(&patch_1).map_err(rlua::Error::external)?
+            } else {
+                Patch::default()
+            };
+
+            let patch_2 = if patch_2 != NULL_SOURCE {
+                let patch_2 = fs::read_to_string(patch_2).map_err(rlua::Error::external)?;
+                PatchProcessor::convert(&patch_2).map_err(rlua::Error::external)?
+            } else {
+                Patch::default()
+            };
+
+            Ok(interdiff_rs::interdiff(patch_1, patch_2, 3).to_string())
+        })?,
+    )?;
+
+    lua.globals().set("interdiff", module)?;
+
+    Ok(())
+}

src/bindings/text/mod.rs

@@ -4,6 +4,7 @@ pub mod patch;
 pub mod scl;
 pub mod select;
 pub mod splitdiff;
+pub mod interdiff;
 pub mod yaml;
 
 use rlua::prelude::*;
@@ -16,6 +17,7 @@ pub fn init(lua: &Lua) -> crate::Result<()> {
     diff::init(&lua)?;
     patch::init(&lua)?;
     splitdiff::init(&lua)?;
+    interdiff::init(&lua)?;
 
     Ok(())
 }