path: root/src/insert.rs

/// The Toml Insert extensions

#[cfg(feature = "typed")]
use serde::Serialize;
use toml::Value;

use crate::error::{Error, Result};
use crate::tokenizer::tokenize_with_seperator;
use crate::tokenizer::Token;

pub trait TomlValueInsertExt {
    /// Extension function for inserting a value in the current toml::Value document
    /// using a custom seperator.
    ///
    /// For difference to TomlSetExt::set() and friends, read [#semantics].
    ///
    /// # Semantics
    ///
    /// The function automatically creates intermediate data structures based on the query string.
    /// That means, if the query string is `"a.b.c.[0]"`, but only a table `"a"` exists in the
    /// document, the function automatically creates a table `"b"` inside `"a"` and `"c"` inside
    /// `"b"`, and an array in `"c"`. The array index is ignored if the array is created.
    ///
    /// If an Array exists, but the specified index is larger than the last index, the array will
    /// be expanded by one element: If the array has a length of 3, but the query string specifies
    /// that the element should be put at 1000, the function ignores the large index and simply
    /// appends the value to the index.
    ///
    /// If a Value is inserted into an Array, the array indexes are shifted. Semantically this is
    /// the same as doing a `array.insert(4, _)` (see the standard library).
    ///
    /// ## Known Bugs
    ///
    /// The current implementation does _not_ create intermediate Arrays as described above.
    /// This is a known bug. So queries like "foo.bar.[0].baz" (or any query which has an array
    /// element) will fail with an error rather than work.
    ///
    /// # Return value
    ///
    /// If the insert operation worked correctly, `Ok(None)` is returned.
    /// If the insert operation replaced an existing value `Ok(Some(old_value))` is returned
    /// On failure, `Err(e)` is returned
    ///
    /// # Examples
    ///
    /// The following example shows a working `insert_with_seperator()` call on an empty toml
    /// document. The Value is inserted as `"foo.bar = 1"` in the document.
    ///
    /// ```rust
    /// extern crate toml;
    /// extern crate toml_query;
    ///
    /// let mut toml : toml::Value = toml::from_str("").unwrap();
    /// let query = "foo.bar";
    /// let sep = '.';
    /// let val = toml::Value::Integer(1);
    ///
    /// let res = toml_query::insert::TomlValueInsertExt::insert_with_seperator(&mut toml, query, sep, val);
    /// assert!(res.is_ok());
    /// let res = res.unwrap();
    /// assert!(res.is_none());
    /// ```
    ///
    /// The following example shows a failing `insert_with_seperator()` call on an empty toml
    /// document. The Query does contain an array token, which does not yet work.
    ///
    /// ```rust,should_panic
    /// extern crate toml;
    /// extern crate toml_query;
    ///
    /// let mut toml : toml::Value = toml::from_str("").unwrap();
    /// let query = "foo.[0]";
    /// let sep = '.';
    /// let val = toml::Value::Integer(1);
    ///
    /// let res = toml_query::insert::TomlValueInsertExt::insert_with_seperator(&mut toml, query, sep, val);
    /// assert!(res.is_ok()); // panics
    /// ```
    ///
    fn insert_with_seperator(
        &mut self,
        query: &str,
        sep: char,
        value: Value,
    ) -> Result<Option<Value>>;

    /// Extension function for inserting a value from the current toml::Value document
    ///
    /// See documentation of `TomlValueinsertExt::insert_with_seperator`
    fn insert(&mut self, query: &str, value: Value) -> Result<Option<Value>> {
        self.insert_with_seperator(query, '.', value)
    }

    /// A convenience method for inserting any arbitrary serializable value.
    #[cfg(feature = "typed")]
    fn insert_serialized<S: Serialize>(&mut self, query: &str, value: S) -> Result<Option<Value>> {
        let value = Value::try_from(value).map_err(Error::TomlSerialize)?;
        self.insert(query, value)
    }
}

impl TomlValueInsertExt for Value {
    fn insert_with_seperator(
        &mut self,
        query: &str,
        sep: char,
        value: Value,
    ) -> Result<Option<Value>> {
        use crate::resolver::mut_creating_resolver::resolve;

        let mut tokens = r#try!(tokenize_with_seperator(query, sep));
        let (val, last) = match tokens.pop_last() {
            None => (self, Box::new(tokens)),
            Some(last) => (r#try!(resolve(self, &tokens)), last),
        };

        match *last {
            Token::Identifier { ident, .. } => match val {
                &mut Value::Table(ref mut t) => Ok(t.insert(ident, value)),
                _ => Err(Error::NoIdentifierInArray(ident.clone())),
            },

            Token::Index { idx, .. } => match val {
                &mut Value::Array(ref mut a) => {
                    if a.len() > idx {
                        a.insert(idx, value);
                        Ok(None)
                    } else {
                        a.push(value);
                        Ok(None)
                    }
                }
                _ => Err(Error::NoIndexInTable(idx)),
            },
        }
    }
}

#[cfg(test)]
mod test {
    use super::*;
    use toml::from_str as toml_from_str;
    use toml::Value;

    #[test]
    fn test_insert_one_token() {
        use toml::map::Map;
        let mut toml = Value::Table(Map::new());

        let res = toml.insert(&String::from("value"), Value::Integer(1));
        println!("TOML: {:?}", toml);
        assert!(res.is_ok());

        let res = res.unwrap();
        assert!(res.is_none());

        assert!(is_match!(toml, Value::Table(_)));
        match toml {
            Value::Table(ref t) => {
                assert!(!t.is_empty());

                let val = t.get("value");
                assert!(
                    val.is_some(),
                    "'value' from table {:?} should be Some(_), is None",
                    t
                );
                let val = val.unwrap();

                assert!(is_match!(val, &Value::Integer(1)), "Is not one: {:?}", val);
            }
            _ => panic!("What just happenend?"),
        }
    }

    #[test]
    fn test_insert_with_seperator_into_table() {
        let mut toml: Value = toml_from_str(
            r#"
        [table]
        "#,
        )
        .unwrap();

        let res = toml.insert_with_seperator(&String::from("table.a"), '.', Value::Integer(1));

        assert!(res.is_ok());

        let res = res.unwrap();
        assert!(res.is_none());

        assert!(is_match!(toml, Value::Table(_)));
        match toml {
            Value::Table(ref t) => {
                assert!(!t.is_empty());

                let table = t.get("table");
                assert!(table.is_some());

                let table = table.unwrap();
                assert!(is_match!(table, &Value::Table(_)));
                match table {
                    &Value::Table(ref t) => {
                        assert!(!t.is_empty());

                        let a = t.get("a");
                        assert!(a.is_some());

                        let a = a.unwrap();
                        assert!(is_match!(a, &Value::Integer(1)));
                    }
                    _ => panic!("What just happenend?"),
                }
            }
            _ => panic!("What just happenend?"),
        }
    }

    #[test]
    fn test_insert_with_seperator_into_array() {
        use std::ops::Index;

        let mut toml: Value = toml_from_str(
            r#"
        array = []
        "#,
        )
        .unwrap();

        let res = toml.insert_with_seperator(&String::from("array.[0]"), '.', Value::Integer(1));

        assert!(res.is_ok());

        let res = res.unwrap();
        assert!(res.is_none());

        assert!(is_match!(toml, Value::Table(_)));
        match toml {
            Value::Table(ref t) => {
                assert!(!t.is_empty());

                let array = t.get("array");
                assert!(array.is_some());

                let array = array.unwrap();
                assert!(is_match!(array, &Value::Array(_)));
                match array {
                    &Value::Array(ref a) => {
                        assert!(!a.is_empty());
                        assert!(is_match!(a.index(0), &Value::Integer(1)));
                    }
                    _ => panic!("What just happenend?"),
                }
            }
            _ => panic!("What just happenend?"),
        }
    }

    #[test]
    fn test_insert_with_seperator_into_nested_table() {
        let mut toml: Value = toml_from_str(
            r#"
<