Handle empty git-config file for parser

This commit is contained in:
Edward Shen 2021-02-20 12:01:38 -05:00
parent 93e6e2eed3
commit 2fb1fa3ff4
Signed by: edward
GPG key ID: 19182661E818369F
3 changed files with 177 additions and 70 deletions

View file

@ -2,14 +2,22 @@ use std::collections::HashMap;
use crate::parser::{parse_from_str, Event, Parser, ParserError}; use crate::parser::{parse_from_str, Event, Parser, ParserError};
#[derive(PartialEq, Eq, Hash, Copy, Clone, PartialOrd, Ord)] #[derive(PartialEq, Eq, Hash, Copy, Clone, PartialOrd, Ord, Debug)]
struct SectionId(usize); struct SectionId(usize);
#[derive(Debug, PartialEq, Eq)]
enum LookupTreeNode<'a> { enum LookupTreeNode<'a> {
Terminal(Vec<SectionId>), Terminal(Vec<SectionId>),
NonTerminal(HashMap<&'a str, Vec<SectionId>>), NonTerminal(HashMap<&'a str, Vec<SectionId>>),
} }
#[derive(Debug, PartialEq, Eq)]
pub enum GitConfigError<'a> {
SectionDoesNotExist(&'a str),
SubSectionDoesNotExist(Option<&'a str>),
KeyDoesNotExist(&'a str),
}
/// High level `git-config` reader and writer. /// High level `git-config` reader and writer.
pub struct GitConfig<'a> { pub struct GitConfig<'a> {
front_matter_events: Vec<Event<'a>>, front_matter_events: Vec<Event<'a>>,
@ -27,14 +35,13 @@ impl<'a> GitConfig<'a> {
} }
pub fn from_parser(parser: Parser<'a>) -> Self { pub fn from_parser(parser: Parser<'a>) -> Self {
// Monotonically increasing let mut new_self = Self {
let mut section_id_counter: usize = 0; front_matter_events: vec![],
sections: HashMap::new(),
// Fields for the struct section_lookup_tree: HashMap::new(),
let mut front_matter_events: Vec<Event<'a>> = vec![]; section_header_separators: HashMap::new(),
let mut sections: HashMap<SectionId, Vec<Event<'a>>> = HashMap::new(); section_id_counter: 0,
let mut section_lookup_tree: HashMap<&str, Vec<LookupTreeNode>> = HashMap::new(); };
let mut section_header_separators = HashMap::new();
// Current section that we're building // Current section that we're building
let mut current_section_name: Option<&str> = None; let mut current_section_name: Option<&str> = None;
@ -45,14 +52,74 @@ impl<'a> GitConfig<'a> {
match event { match event {
e @ Event::Comment(_) => match maybe_section { e @ Event::Comment(_) => match maybe_section {
Some(ref mut section) => section.push(e), Some(ref mut section) => section.push(e),
None => front_matter_events.push(e), None => new_self.front_matter_events.push(e),
}, },
Event::SectionHeader(header) => { Event::SectionHeader(header) => {
// Push current section to struct new_self.push_section(
let new_section_id = SectionId(section_id_counter); &mut current_section_name,
&mut current_subsection_name,
&mut maybe_section,
);
// 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);
}
e @ Event::Key(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Value(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Newline(_) => match maybe_section {
Some(ref mut section) => section.push(e),
None => new_self.front_matter_events.push(e),
},
e @ Event::ValueNotDone(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::ValueDone(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Whitespace(_) => match maybe_section {
Some(ref mut section) => section.push(e),
None => new_self.front_matter_events.push(e),
},
}
}
new_self.push_section(
&mut current_section_name,
&mut current_subsection_name,
&mut maybe_section,
);
new_self
}
fn push_section(
&mut self,
current_section_name: &mut Option<&'a str>,
current_subsection_name: &mut Option<&'a str>,
maybe_section: &mut Option<Vec<Event<'a>>>,
) {
let new_section_id = SectionId(self.section_id_counter);
if let Some(section) = maybe_section.take() { if let Some(section) = maybe_section.take() {
sections.insert(new_section_id, section); self.sections.insert(new_section_id, section);
let lookup = section_lookup_tree let lookup = self
.section_lookup_tree
.entry(current_section_name.unwrap()) .entry(current_section_name.unwrap())
.or_default(); .or_default();
@ -70,7 +137,7 @@ impl<'a> GitConfig<'a> {
} }
if !found_node { if !found_node {
let mut map = HashMap::new(); let mut map = HashMap::new();
map.insert(subsection_name, vec![new_section_id]); map.insert(*subsection_name, vec![new_section_id]);
lookup.push(LookupTreeNode::NonTerminal(map)); lookup.push(LookupTreeNode::NonTerminal(map));
} }
} else { } else {
@ -85,57 +152,36 @@ impl<'a> GitConfig<'a> {
lookup.push(LookupTreeNode::Terminal(vec![new_section_id])) lookup.push(LookupTreeNode::Terminal(vec![new_section_id]))
} }
} }
self.section_id_counter += 1;
section_id_counter += 1;
}
// 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.
section_header_separators
.insert(SectionId(section_id_counter), header.separator);
}
e @ Event::Key(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Value(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Newline(_) => match maybe_section {
Some(ref mut section) => section.push(e),
None => front_matter_events.push(e),
},
e @ Event::ValueNotDone(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::ValueDone(_) => maybe_section
.as_mut()
.expect("Got a section-only event before a section")
.push(e),
e @ Event::Whitespace(_) => match maybe_section {
Some(ref mut section) => section.push(e),
None => front_matter_events.push(e),
},
}
}
Self {
front_matter_events,
section_lookup_tree,
sections,
section_header_separators,
section_id_counter,
} }
} }
/// Returns an uninterpreted value given a section and optional subsection
/// and key.
///
/// Note that `git-config` follows a "last-one-wins" rule for single values.
/// If multiple sections contain the same key, then the last section's last
/// key's value will be returned.
///
/// Concretely, if you have the following config:
///
/// ```text
/// [core]
/// a = b
/// [core]
/// a = c
/// a = d
/// ```
///
/// Then this function will return `d`:
///
/// ```
/// # use serde_git_config::config::GitConfig;
/// # let git_config = GitConfig::from_str("[core]a=b\n[core]\na=c\na=d").unwrap();
/// assert_eq!(git_config.get_raw_single_value("core", None, "a"), Ok("d"));
/// ```
///
/// The the resolution is as follows
pub fn get_raw_single_value<'b>( pub fn get_raw_single_value<'b>(
&self, &self,
section_name: &'b str, section_name: &'b str,
@ -153,15 +199,20 @@ impl<'a> GitConfig<'a> {
// violated invariant. // violated invariant.
let events = self.sections.get(&section_id).unwrap(); let events = self.sections.get(&section_id).unwrap();
let mut found_key = false; let mut found_key = false;
let mut latest_value = None;
// logic needs fixing for last one wins rule
for event in events { for event in events {
match event { match event {
Event::Key(event_key) if *event_key == key => found_key = true, Event::Key(event_key) if *event_key == key => found_key = true,
Event::Value(v) if found_key => return Ok(v), Event::Value(v) if found_key => {
found_key = false;
latest_value = Some(*v);
}
_ => (), _ => (),
} }
} }
Err(GitConfigError::KeyDoesNotExist(key)) latest_value.ok_or(GitConfigError::KeyDoesNotExist(key))
} }
fn get_section_id_by_name_and_subname<'b>( fn get_section_id_by_name_and_subname<'b>(
@ -236,8 +287,61 @@ impl<'a> GitConfig<'a> {
} }
} }
pub enum GitConfigError<'a> { #[cfg(test)]
SectionDoesNotExist(&'a str), mod git_config {
SubSectionDoesNotExist(Option<&'a str>), mod from_parser {
KeyDoesNotExist(&'a str), use super::super::*;
#[test]
fn parse_empty() {
let config = GitConfig::from_str("").unwrap();
assert!(config.section_header_separators.is_empty());
assert_eq!(config.section_id_counter, 0);
assert!(config.section_lookup_tree.is_empty());
assert!(config.sections.is_empty());
}
#[test]
fn parse_single_section() {
let config = GitConfig::from_str("[core]\na=b\nc=d").unwrap();
let expected_separators = {
let mut map = HashMap::new();
map.insert(SectionId(0), None);
map
};
assert_eq!(config.section_header_separators, expected_separators);
assert_eq!(config.section_id_counter, 1);
let expected_lookup_tree = {
let mut tree = HashMap::new();
tree.insert("core", vec![LookupTreeNode::Terminal(vec![SectionId(0)])]);
tree
};
assert_eq!(config.section_lookup_tree, expected_lookup_tree);
let expected_sections = {
let mut sections = HashMap::new();
sections.insert(
SectionId(0),
vec![
Event::Newline("\n"),
Event::Key("a"),
Event::Value("b"),
Event::Newline("\n"),
Event::Key("c"),
Event::Value("d"),
],
);
sections
};
assert_eq!(config.sections, expected_sections);
}
#[test]
fn parse_single_subsection() {}
#[test]
fn parse_multiple_sections() {}
#[test]
fn parse_multiple_duplicate_sections() {}
}
} }

View file

@ -12,7 +12,6 @@ use nom::character::complete::{char, none_of, one_of};
use nom::character::{is_newline, is_space}; use nom::character::{is_newline, is_space};
use nom::combinator::{map, opt}; use nom::combinator::{map, opt};
use nom::error::{Error as NomError, ErrorKind}; use nom::error::{Error as NomError, ErrorKind};
use nom::multi::many1;
use nom::sequence::delimited; use nom::sequence::delimited;
use nom::IResult; use nom::IResult;
use nom::{branch::alt, multi::many0}; use nom::{branch::alt, multi::many0};
@ -360,7 +359,7 @@ impl<'a> Parser<'a> {
/// data succeeding valid `git-config` data. /// data succeeding valid `git-config` data.
pub fn parse_from_str(input: &str) -> Result<Parser<'_>, ParserError> { pub fn parse_from_str(input: &str) -> Result<Parser<'_>, ParserError> {
let (i, comments) = many0(comment)(input)?; let (i, comments) = many0(comment)(input)?;
let (i, sections) = many1(section)(i)?; let (i, sections) = many0(section)(i)?;
if !i.is_empty() { if !i.is_empty() {
return Err(ParserError::ConfigHasExtraData(i)); return Err(ParserError::ConfigHasExtraData(i));

View file

@ -62,8 +62,7 @@ fn personal_config() {
assert_eq!( assert_eq!(
parse_from_str(config) parse_from_str(config)
.unwrap() .unwrap()
.into_iter() .into_vec(),
.collect::<Vec<_>>(),
vec![ vec![
gen_section_header("user", None), gen_section_header("user", None),
newline(), newline(),
@ -163,3 +162,8 @@ fn personal_config() {
] ]
); );
} }
#[test]
fn parse_empty() {
assert_eq!(parse_from_str("").unwrap().into_vec(), vec![]);
}