Don't error on empty input

CHANGELOG.md

@@ -1,6 +1,10 @@
 # CHANGELOG
 
 ## [Unreleased]
+### Breaking
+
+- `Patch::from_multiple` no longer returns an error on an input that contains no patches, including an empty string. It instead returns an empty vector.
+
 ### Changed
 
 ## [v0.7]

src/ast.rs

@@ -81,7 +81,9 @@ impl<'a> Patch<'a> {
     }
 
     /// Attempt to parse as many patches as possible from the given string. This is useful for when
-    /// you have a complete diff of many files. String must contain at least one patch.
+    /// you have a complete diff of many files.
+    ///
+    /// It is not an error if the string contains no patches: this returns an empty vector.
     ///
     /// # Example
     ///
@@ -299,7 +301,7 @@ mod tests {
             range_hint: "",
             lines: vec![],
         };
-        for (input, expected) in vec![
+        for (input, expected) in [
             ("", None),
             (" ", None),
             ("  ", None),

src/parser.rs

@@ -2,13 +2,12 @@ use std::borrow::Cow;
 use std::error::Error;
 
 use chrono::DateTime;
-use nom::combinator::verify;
 use nom::*;
 use nom::{
     branch::alt,
     bytes::complete::{is_not, tag, take_until},
     character::complete::{char, digit1, line_ending, none_of, not_line_ending, one_of},
-    combinator::{map, map_opt, not, opt},
+    combinator::{all_consuming, map, map_opt, not, opt, verify},
     error::context,
     multi::{many0, many1},
     sequence::{delimited, preceded, terminated, tuple},
@@ -82,20 +81,15 @@ pub(crate) fn parse_single_patch(s: &str) -> Result<Patch<'_>, ParseError<'_>> {
 
 pub(crate) fn parse_multiple_patches(s: &str) -> Result<Vec<Patch<'_>>, ParseError<'_>> {
     let (remaining_input, patches) = multiple_patches(Input::new(s))?;
-    // Parser should return an error instead of producing remaining input
-    if !remaining_input.fragment().is_empty() {
-        return Err(ParseError {
-            line: remaining_input.location_line(),
-            offset: remaining_input.location_offset(),
-            fragment: remaining_input.fragment(),
-            kind: nom::error::ErrorKind::Eof,
-        });
-    }
+    debug_assert!(
+        remaining_input.fragment().is_empty(),
+        "all_consuming should not have left over input"
+    );
     Ok(patches)
 }
 
 fn multiple_patches(input: Input) -> IResult<Input, Vec<Patch>> {
-    many1(patch)(input)
+    all_consuming(many0(patch))(input)
 }
 
 fn patch(input: Input) -> IResult<Input, Patch> {
@@ -424,6 +418,12 @@ mod tests {
         Ok(())
     }
 
+    #[test]
+    fn test_empty_input() -> ParseResult<'static, ()> {
+        test_parser!(multiple_patches("") -> @("", Vec::new()));
+        Ok(())
+    }
+
     #[test]
     fn test_filename() -> ParseResult<'static, ()> {
         // bare