gitconfig writing to string

src/config.rs

@@ -1,7 +1,7 @@
-use crate::parser::{parse_from_str, Event, Parser, ParserError};
+use crate::parser::{parse_from_str, Event, ParsedSectionHeader, Parser, ParserError};
 use serde::Serialize;
-use std::borrow::Cow;
 use std::collections::{HashMap, VecDeque};
+use std::{borrow::Cow, fmt::Display};
 
 #[derive(Debug, PartialEq, Eq)]
 pub enum GitConfigError<'a> {
@@ -23,7 +23,7 @@ pub struct GitConfig<'a> {
     /// SectionId to section mapping. The value of this HashMap contains actual
     /// events
     sections: HashMap<SectionId, Vec<Event<'a>>>,
-    section_header_separators: HashMap<SectionId, Option<Cow<'a, str>>>,
+    section_headers: HashMap<SectionId, ParsedSectionHeader<'a>>,
     section_id_counter: usize,
     section_order: VecDeque<SectionId>,
 }
@@ -60,7 +60,7 @@ impl<'a> GitConfig<'a> {
             front_matter_events: vec![],
             sections: HashMap::new(),
             section_lookup_tree: HashMap::new(),
-            section_header_separators: HashMap::new(),
+            section_headers: HashMap::new(),
             section_id_counter: 0,
             section_order: VecDeque::new(),
         };
@@ -80,16 +80,16 @@ impl<'a> GitConfig<'a> {
                     );
 
                     // Initialize new section
-                    let (name, subname) = (header.name, header.subsection_name);
-                    maybe_section = Some(vec![]);
-                    current_section_name = Some(name);
-                    current_subsection_name = subname;
                     // We need to store the new, current id counter, so don't
                     // use new_section_id here and use the already incremented
                     // section id value.
                     new_self
-                        .section_header_separators
-                        .insert(SectionId(new_self.section_id_counter), header.separator);
+                        .section_headers
+                        .insert(SectionId(new_self.section_id_counter), header.clone());
+                    let (name, subname) = (header.name, header.subsection_name);
+                    maybe_section = Some(vec![]);
+                    current_section_name = Some(name);
+                    current_subsection_name = subname;
                 }
                 e @ Event::Key(_)
                 | e @ Event::Value(_)
@@ -513,6 +513,62 @@ impl<'a> GitConfig<'a> {
         *value = new_value.into();
         Ok(())
     }
+
+    /// Sets a multivar in a given section, optional subsection, and key value.
+    ///
+    /// This internally zips together the new values and the existing values.
+    /// As a result, if more new values are provided than the current amount of
+    /// multivars, then the latter values are not applied. If there are less
+    /// new values than old ones then the remaining old values are unmodified.
+    ///
+    /// If you need finer control over which values of the multivar are set,
+    /// consider using [`get_raw_multi_value_mut`].
+    ///
+    /// todo: examples and errors
+    ///
+    /// [`get_raw_multi_value_mut`]: Self::get_raw_multi_value_mut
+    pub fn set_raw_multi_value<'b>(
+        &mut self,
+        section_name: &'b str,
+        subsection_name: Option<&'b str>,
+        key: &'b str,
+        new_values: Vec<Cow<'a, str>>,
+    ) -> Result<(), GitConfigError<'b>> {
+        let values = self.get_raw_multi_value_mut(section_name, subsection_name, key)?;
+        for (old, new) in values.into_iter().zip(new_values) {
+            *old = new;
+        }
+        Ok(())
+    }
+}
+
+impl Display for GitConfig<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        for front_matter in &self.front_matter_events {
+            front_matter.fmt(f)?;
+        }
+
+        for section_id in &self.section_order {
+            self.section_headers.get(section_id).unwrap().fmt(f)?;
+            let mut found_key = false;
+            for event in self.sections.get(section_id).unwrap() {
+                match event {
+                    Event::Key(k) => {
+                        found_key = true;
+                        k.fmt(f)?;
+                    }
+                    Event::Whitespace(w) if found_key => {
+                        found_key = false;
+                        w.fmt(f)?;
+                        write!(f, "=")?;
+                    }
+                    e => e.fmt(f)?,
+                }
+            }
+        }
+
+        Ok(())
+    }
 }
 
 #[cfg(test)]
@@ -522,7 +578,7 @@ mod from_parser {
     #[test]
     fn parse_empty() {
         let config = GitConfig::from_str("").unwrap();
-        assert!(config.section_header_separators.is_empty());
+        assert!(config.section_headers.is_empty());
         assert_eq!(config.section_id_counter, 0);
         assert!(config.section_lookup_tree.is_empty());
         assert!(config.sections.is_empty());
@@ -534,10 +590,17 @@ mod from_parser {
         let mut config = GitConfig::from_str("[core]\na=b\nc=d").unwrap();
         let expected_separators = {
             let mut map = HashMap::new();
-            map.insert(SectionId(0), None);
+            map.insert(
+                SectionId(0),
+                ParsedSectionHeader {
+                    name: "core".into(),
+                    separator: None,
+                    subsection_name: None,
+                },
+            );
             map
         };
-        assert_eq!(config.section_header_separators, expected_separators);
+        assert_eq!(config.section_headers, expected_separators);
         assert_eq!(config.section_id_counter, 1);
         let expected_lookup_tree = {
             let mut tree = HashMap::new();
@@ -572,10 +635,17 @@ mod from_parser {
         let mut config = GitConfig::from_str("[core.subsec]\na=b\nc=d").unwrap();
         let expected_separators = {
             let mut map = HashMap::new();
-            map.insert(SectionId(0), Some(Cow::Borrowed(".")));
+            map.insert(
+                SectionId(0),
+                ParsedSectionHeader {
+                    name: "core".into(),
+                    separator: Some(".".into()),
+                    subsection_name: Some("subsec".into()),
+                },
+            );
             map
         };
-        assert_eq!(config.section_header_separators, expected_separators);
+        assert_eq!(config.section_headers, expected_separators);
         assert_eq!(config.section_id_counter, 1);
         let expected_lookup_tree = {
             let mut tree = HashMap::new();
@@ -612,11 +682,25 @@ mod from_parser {
         let mut config = GitConfig::from_str("[core]\na=b\nc=d\n[other]e=f").unwrap();
         let expected_separators = {
             let mut map = HashMap::new();
-            map.insert(SectionId(0), None);
-            map.insert(SectionId(1), None);
+            map.insert(
+                SectionId(0),
+                ParsedSectionHeader {
+                    name: "core".into(),
+                    separator: None,
+                    subsection_name: None,
+                },
+            );
+            map.insert(
+                SectionId(1),
+                ParsedSectionHeader {
+                    name: "other".into(),
+                    separator: None,
+                    subsection_name: None,
+                },
+            );
             map
         };
-        assert_eq!(config.section_header_separators, expected_separators);
+        assert_eq!(config.section_headers, expected_separators);
         assert_eq!(config.section_id_counter, 2);
         let expected_lookup_tree = {
             let mut tree = HashMap::new();
@@ -666,11 +750,25 @@ mod from_parser {
         let mut config = GitConfig::from_str("[core]\na=b\nc=d\n[core]e=f").unwrap();
         let expected_separators = {
             let mut map = HashMap::new();
-            map.insert(SectionId(0), None);
-            map.insert(SectionId(1), None);
+            map.insert(
+                SectionId(0),
+                ParsedSectionHeader {
+                    name: "core".into(),
+                    separator: None,
+                    subsection_name: None,
+                },
+            );
+            map.insert(
+                SectionId(1),
+                ParsedSectionHeader {
+                    name: "core".into(),
+                    separator: None,
+                    subsection_name: None,
+                },
+            );
             map
         };
-        assert_eq!(config.section_header_separators, expected_separators);
+        assert_eq!(config.section_headers, expected_separators);
         assert_eq!(config.section_id_counter, 2);
         let expected_lookup_tree = {
             let mut tree = HashMap::new();
@@ -868,3 +966,41 @@ mod get_raw_multi_value {
         );
     }
 }
+
+#[cfg(test)]
+mod display {
+    use super::*;
+
+    #[test]
+    fn can_reconstruct_empty_config() {
+        let config = r#"
+
+        "#;
+        assert_eq!(GitConfig::from_str(config).unwrap().to_string(), config);
+    }
+
+    #[test]
+    fn can_reconstruct_non_empty_config() {
+        let config = r#"[user]
+        email = code@eddie.sh
+        name = Edward Shen
+[core]
+        autocrlf = input
+[push]
+        default = simple
+[commit]
+        gpgsign = true
+[gpg]
+        program = gpg
+[url "ssh://git@github.com/"]
+        insteadOf = "github://"
+[url "ssh://git@git.eddie.sh/edward/"]
+        insteadOf = "gitea://"
+[pull]
+        ff = only
+[init]
+        defaultBranch = master"#;
+
+        assert_eq!(GitConfig::from_str(config).unwrap().to_string(), config);
+    }
+}

src/parser.rs

@@ -17,7 +17,9 @@ use nom::error::{Error as NomError, ErrorKind};
 use nom::sequence::delimited;
 use nom::IResult;
 use nom::{branch::alt, multi::many0};
-use std::{borrow::Cow, iter::FusedIterator};
+use std::borrow::{Borrow, Cow};
+use std::fmt::Display;
+use std::iter::FusedIterator;
 
 /// Syntactic events that occurs in the config.
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug)]
@@ -38,7 +40,8 @@ pub enum Event<'a> {
     Value(Cow<'a, str>),
     /// Represents any token used to signify a new line character. On Unix
     /// platforms, this is typically just `\n`, but can be any valid newline
-    /// sequence.
+    /// sequence. Multiple newlines (such as `\n\n`) will be merged as a single
+    /// newline event.
     Newline(Cow<'a, str>),
     /// Any value that isn't completed. This occurs when the value is continued
     /// onto the next line. A Newline event is guaranteed after, followed by
@@ -51,6 +54,21 @@ pub enum Event<'a> {
     Whitespace(Cow<'a, str>),
 }
 
+impl Display for Event<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        match self {
+            Self::Comment(e) => e.fmt(f),
+            Self::SectionHeader(e) => e.fmt(f),
+            Self::Key(e) => e.fmt(f),
+            Self::Value(e) => e.fmt(f),
+            Self::Newline(e) => e.fmt(f),
+            Self::ValueNotDone(e) => e.fmt(f),
+            Self::ValueDone(e) => e.fmt(f),
+            Self::Whitespace(e) => e.fmt(f),
+        }
+    }
+}
+
 /// A parsed section containing the header and the section events.
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Default)]
 pub struct ParsedSection<'a> {
@@ -59,6 +77,15 @@ pub struct ParsedSection<'a> {
     /// The syntactic events found in this section.
     pub events: Vec<Event<'a>>,
 }
+impl Display for ParsedSection<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "{}", self.section_header)?;
+        for event in &self.events {
+            event.fmt(f)?;
+        }
+        Ok(())
+    }
+}
 
 /// A parsed section header, containing a name and optionally a subsection name.
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Default)]
@@ -75,6 +102,23 @@ pub struct ParsedSectionHeader<'a> {
     pub subsection_name: Option<Cow<'a, str>>,
 }
 
+impl Display for ParsedSectionHeader<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        write!(f, "[{}", self.name)?;
+
+        if let Some(v) = &self.separator {
+            v.fmt(f)?;
+            let subsection_name = self.subsection_name.as_ref().unwrap();
+            match v.borrow() {
+                "." => subsection_name.fmt(f)?,
+                _ => write!(f, "\"{}\"", subsection_name)?,
+            }
+        }
+
+        write!(f, "]")
+    }
+}
+
 /// A parsed comment event containing the comment marker and comment.
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Default)]
 pub struct ParsedComment<'a> {
@@ -84,6 +128,13 @@ pub struct ParsedComment<'a> {
     pub comment: Cow<'a, str>,
 }
 
+impl Display for ParsedComment<'_> {
+    fn fmt(&self, f: &mut std::fmt::Formatter<'_>) -> std::fmt::Result {
+        self.comment_tag.fmt(f)?;
+        self.comment.fmt(f)
+    }
+}
+
 /// The various parsing failure reasons.
 #[derive(PartialEq, Debug)]
 pub enum ParserError<'a> {
@@ -275,7 +326,7 @@ impl<'a> From<nom::Err<NomError<&'a str>>> for ParserError<'a> {
 /// [`FromStr`]: std::str::FromStr
 #[derive(Clone, Eq, PartialEq, Ord, PartialOrd, Hash, Debug, Default)]
 pub struct Parser<'a> {
-    init_comments: Vec<ParsedComment<'a>>,
+    frontmatter: Vec<Event<'a>>,
     sections: Vec<ParsedSection<'a>>,
 }
 
@@ -296,20 +347,21 @@ impl<'a> Parser<'a> {
         parse_from_str(s)
     }
 
-    /// Returns the leading comments (any comments before a section) from the
-    /// parser. Consider [`Parser::take_leading_comments`] if you need an owned
-    /// copy only once. If that function was called, then this will always
-    /// return an empty slice.
-    pub fn leading_comments(&self) -> &[ParsedComment<'a>] {
-        &self.init_comments
+    /// Returns the leading events (any comments, whitespace, or newlines before
+    /// a section) from the parser. Consider [`Parser::take_frontmatter`] if
+    /// you need an owned copy only once. If that function was called, then this
+    /// will always return an empty slice.
+    pub fn frontmatter(&self) -> &[Event<'a>] {
+        &self.frontmatter
     }
 
-    /// Takes the leading comments (any comments before a section) from the
-    /// parser. Subsequent calls will return an empty vec. Consider
-    /// [`Parser::leading_comments`] if you only need a reference to the comments.
-    pub fn take_leading_comments(&mut self) -> Vec<ParsedComment<'a>> {
+    /// Takes the leading events (any comments, whitespace, or newlines before
+    /// a section) from the parser. Subsequent calls will return an empty vec.
+    /// Consider [`Parser::frontmatter`] if you only need a reference to the
+    /// frontmatter
+    pub fn take_frontmatter(&mut self) -> Vec<Event<'a>> {
         let mut to_return = vec![];
-        std::mem::swap(&mut self.init_comments, &mut to_return);
+        std::mem::swap(&mut self.frontmatter, &mut to_return);
         to_return
     }
 
@@ -345,10 +397,7 @@ impl<'a> Parser<'a> {
                     .chain(section.events)
             })
             .flatten();
-        self.init_comments
-            .into_iter()
-            .map(Event::Comment)
-            .chain(section_iter)
+        self.frontmatter.into_iter().chain(section_iter)
     }
 }
 
@@ -363,7 +412,13 @@ impl<'a> Parser<'a> {
 /// This generally is due to either invalid names or if there's extraneous
 /// data succeeding valid `git-config` data.
 pub fn parse_from_str(input: &str) -> Result<Parser<'_>, ParserError> {
-    let (i, comments) = many0(comment)(input)?;
+    let (i, frontmatter) = many0(alt((
+        map(comment, |comment| Event::Comment(comment)),
+        map(take_spaces, |whitespace| {
+            Event::Whitespace(whitespace.into())
+        }),
+        map(take_newline, |newline| Event::Newline(newline.into())),
+    )))(input)?;
     let (i, sections) = many0(section)(i)?;
 
     if !i.is_empty() {
@@ -371,7 +426,7 @@ pub fn parse_from_str(input: &str) -> Result<Parser<'_>, ParserError> {
     }
 
     Ok(Parser {
-        init_comments: comments,
+        frontmatter,
         sections,
     })
 }

tests/parser_integration_tests.rs

@@ -170,3 +170,25 @@ fn personal_config() {
 fn parse_empty() {
     assert_eq!(parse_from_str("").unwrap().into_vec(), vec![]);
 }
+
+#[test]
+fn parse_whitespace() {
+    assert_eq!(
+        parse_from_str("\n   \n \n").unwrap().into_vec(),
+        vec![
+            newline(),
+            whitespace("   "),
+            newline(),
+            whitespace(" "),
+            newline(),
+        ]
+    )
+}
+
+#[test]
+fn newline_events_are_merged() {
+    assert_eq!(
+        parse_from_str("\n\n\n\n\n").unwrap().into_vec(),
+        vec![Event::Newline("\n\n\n\n\n".into())]
+    );
+}