//! Module containing the error type returned by TinyTemplate if an error occurs. | |
use instruction::{path_to_str, PathSlice}; | |
use serde_json::Error as SerdeJsonError; | |
use serde_json::Value; | |
use std::error::Error as StdError; | |
use std::fmt; | |
/// Enum representing the potential errors that TinyTemplate can encounter. | |
#[derive(Debug)] | |
pub enum Error { | |
ParseError { | |
msg: String, | |
line: usize, | |
column: usize, | |
}, | |
RenderError { | |
msg: String, | |
line: usize, | |
column: usize, | |
}, | |
SerdeError { | |
err: SerdeJsonError, | |
}, | |
GenericError { | |
msg: String, | |
}, | |
StdFormatError { | |
err: fmt::Error, | |
}, | |
CalledTemplateError { | |
name: String, | |
err: Box<Error>, | |
line: usize, | |
column: usize, | |
}, | |
CalledFormatterError { | |
name: String, | |
err: Box<Error>, | |
line: usize, | |
column: usize, | |
}, | |
#[doc(hidden)] | |
__NonExhaustive, | |
} | |
impl From<SerdeJsonError> for Error { | |
fn from(err: SerdeJsonError) -> Error { | |
Error::SerdeError { err } | |
} | |
} | |
impl From<fmt::Error> for Error { | |
fn from(err: fmt::Error) -> Error { | |
Error::StdFormatError { err } | |
} | |
} | |
impl fmt::Display for Error { | |
fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { | |
match self { | |
Error::ParseError { msg, line, column } => write!( | |
f, | |
"Failed to parse the template (line {}, column {}). Reason: {}", | |
line, column, msg | |
), | |
Error::RenderError { msg, line, column } => { | |
write!( | |
f, | |
"Encountered rendering error on line {}, column {}. Reason: {}", | |
line, column, msg | |
) | |
} | |
Error::SerdeError { err } => { | |
write!(f, "Unexpected serde error while converting the context to a serde_json::Value. Error: {}", err) | |
} | |
Error::GenericError { msg } => { | |
write!(f, "{}", msg) | |
} | |
Error::StdFormatError { err } => { | |
write!(f, "Unexpected formatting error: {}", err) | |
} | |
Error::CalledTemplateError { | |
name, | |
err, | |
line, | |
column, | |
} => { | |
write!( | |
f, | |
"Call to sub-template \"{}\" on line {}, column {} failed. Reason: {}", | |
name, line, column, err | |
) | |
} | |
Error::CalledFormatterError { | |
name, | |
err, | |
line, | |
column, | |
} => { | |
write!( | |
f, | |
"Call to value formatter \"{}\" on line {}, column {} failed. Reason: {}", | |
name, line, column, err | |
) | |
} | |
Error::__NonExhaustive => unreachable!(), | |
} | |
} | |
} | |
impl StdError for Error { | |
fn description(&self) -> &str { | |
match self { | |
Error::ParseError { .. } => "ParseError", | |
Error::RenderError { .. } => "RenderError", | |
Error::SerdeError { .. } => "SerdeError", | |
Error::GenericError { msg } => &msg, | |
Error::StdFormatError { .. } => "StdFormatError", | |
Error::CalledTemplateError { .. } => "CalledTemplateError", | |
Error::CalledFormatterError { .. } => "CalledFormatterError", | |
Error::__NonExhaustive => unreachable!(), | |
} | |
} | |
} | |
pub type Result<T> = ::std::result::Result<T, Error>; | |
pub(crate) fn lookup_error(source: &str, step: &str, path: PathSlice, current: &Value) -> Error { | |
let avail_str = if let Value::Object(object_map) = current { | |
let mut avail_str = " Available values at this level are ".to_string(); | |
for (i, key) in object_map.keys().enumerate() { | |
if i > 0 { | |
avail_str.push_str(", "); | |
} | |
avail_str.push('\''); | |
avail_str.push_str(key); | |
avail_str.push('\''); | |
} | |
avail_str | |
} else { | |
"".to_string() | |
}; | |
let (line, column) = get_offset(source, step); | |
Error::RenderError { | |
msg: format!( | |
"Failed to find value '{}' from path '{}'.{}", | |
step, | |
path_to_str(path), | |
avail_str | |
), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn truthiness_error(source: &str, path: PathSlice) -> Error { | |
let (line, column) = get_offset(source, path.last().unwrap()); | |
Error::RenderError { | |
msg: format!( | |
"Path '{}' produced a value which could not be checked for truthiness.", | |
path_to_str(path) | |
), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn unprintable_error() -> Error { | |
Error::GenericError { | |
msg: "Expected a printable value but found array or object.".to_string(), | |
} | |
} | |
pub(crate) fn not_iterable_error(source: &str, path: PathSlice) -> Error { | |
let (line, column) = get_offset(source, path.last().unwrap()); | |
Error::RenderError { | |
msg: format!( | |
"Expected an array for path '{}' but found a non-iterable value.", | |
path_to_str(path) | |
), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn unknown_template(source: &str, name: &str) -> Error { | |
let (line, column) = get_offset(source, name); | |
Error::RenderError { | |
msg: format!("Tried to call an unknown template '{}'", name), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn unknown_formatter(source: &str, name: &str) -> Error { | |
let (line, column) = get_offset(source, name); | |
Error::RenderError { | |
msg: format!("Tried to call an unknown formatter '{}'", name), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn called_template_error(source: &str, template_name: &str, err: Error) -> Error { | |
let (line, column) = get_offset(source, template_name); | |
Error::CalledTemplateError { | |
name: template_name.to_string(), | |
err: Box::new(err), | |
line, | |
column, | |
} | |
} | |
pub(crate) fn called_formatter_error(source: &str, formatter_name: &str, err: Error) -> Error { | |
let (line, column) = get_offset(source, formatter_name); | |
Error::CalledFormatterError { | |
name: formatter_name.to_string(), | |
err: Box::new(err), | |
line, | |
column, | |
} | |
} | |
/// Find the line number and column of the target string within the source string. Will panic if | |
/// target is not a substring of source. | |
pub(crate) fn get_offset(source: &str, target: &str) -> (usize, usize) { | |
let offset = target.as_ptr() as isize - source.as_ptr() as isize; | |
let to_scan = &source[0..(offset as usize)]; | |
let mut line = 1; | |
let mut column = 0; | |
for byte in to_scan.bytes() { | |
match byte as char { | |
'\n' => { | |
line += 1; | |
column = 0; | |
} | |
_ => { | |
column += 1; | |
} | |
} | |
} | |
(line, column) | |
} |