lix/tests/errors/main.cc
2020-04-02 14:08:05 -06:00

92 lines
3 KiB
C++

#include "../../src/libutil/error.hh"
#include <optional>
#include <iostream>
int main()
{
using namespace nix;
// In each program where errors occur, this has to be set.
ErrorInfo::programName = std::optional("error-test");
// There are currently four error types:
//
// ProgramError, ProgramWarning, NixLangError, NixLangWarning.
//
// Each error type is created with a specific sequence of builder functions.
// Unlike with a constructor, each parameter is clearly named.
// If the sequence of function calls isn't followed, then there's a type error.
// This should make for a consistent look in the code when errors are created.
// ProgramError takes name, description, and an optional hint.
printErrorInfo(
ProgramError()
.name("name")
.description("error description")
.nohint()
);
// ProgramWarning takes name, description, and an optional hint.
// The hint is in the form of a hintfmt class, which wraps boost::format(), and
// makes all the substituted text yellow.
printErrorInfo(
ProgramWarning()
.name("warning name")
.description("warning description")
.hint(hintfmt("there was a %1%") % "warning") // 'warning' will be yellow.
);
/*
// some invalid errors:
// type error: no hint function.
ProgramError()
.name("name")
.description("error description");
// type error: description before name.
ProgramError()
.description("error description")
.name("name")
.nohint();
// type error: hint function with regular boost format, not special hintfmt.
ProgramError()
.description("error description")
.name("name")
.hint(format("there was a %1%") % "warning");
*/
// NixLangWarning adds nix file, line number, column range, and the lines of code
// where a warning occurred.
printErrorInfo(
NixLangWarning()
.name("warning name")
.description("warning description")
.nixFile("myfile.nix")
.lineNumber(40)
.columnRange(13,7)
.linesOfCode(std::nullopt
,"this is the problem line of code"
,std::nullopt)
.hint(hintfmt("this hint has %1% templated %2%!!") % "yellow" % "values")
);
// NixLangError is just the same as NixLangWarning, except for the Error flag.
printErrorInfo(
NixLangError()
.name("error name")
.description("error description")
.nixFile("myfile.nix")
.lineNumber(40)
.columnRange(13,7)
.linesOfCode(std::optional("previous line of code")
,"this is the problem line of code"
,std::optional("next line of code"))
.hint(hintfmt("this hint has %1% templated %2%!!") % "yellow" % "values")
);
return 0;
}