From 55849e153e4b28d03bfca1738c415c438c60f9f6 Mon Sep 17 00:00:00 2001
From: Eelco Dolstra <edolstra@gmail.com>
Date: Thu, 21 Jan 2021 00:55:59 +0100
Subject: [PATCH] Change error position formatting

It's now

  at /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix:7:7:

instead of

  at: (7:7) in file: /home/eelco/Dev/nixpkgs/pkgs/applications/misc/hello/default.nix

The new format is more standard and clickable.
---
 src/libutil/error.cc | 22 +++++++++-------------
 tests/misc.sh        |  4 ++--
 2 files changed, 11 insertions(+), 15 deletions(-)

diff --git a/src/libutil/error.cc b/src/libutil/error.cc
index ddeb5412a..5d570a75e 100644
--- a/src/libutil/error.cc
+++ b/src/libutil/error.cc
@@ -43,9 +43,9 @@ string showErrPos(const ErrPos & errPos)
 {
     if (errPos.line > 0) {
         if (errPos.column > 0) {
-            return fmt("(%1%:%2%)", errPos.line, errPos.column);
+            return fmt("%d:%d", errPos.line, errPos.column);
         } else {
-            return fmt("(%1%)", errPos.line);
+            return fmt("%d", errPos.line);
         }
     }
     else {
@@ -178,24 +178,20 @@ void printCodeLines(std::ostream & out,
     }
 }
 
-void printAtPos(const string & prefix, const ErrPos & pos, std::ostream & out)
+void printAtPos(const ErrPos & pos, std::ostream & out)
 {
-    if (pos)
-    {
+    if (pos) {
         switch (pos.origin) {
             case foFile: {
-                out << prefix << ANSI_BLUE << "at: " << ANSI_YELLOW << showErrPos(pos) <<
-                    ANSI_BLUE << " in file: " << ANSI_NORMAL << pos.file;
+                out << fmt(ANSI_BLUE "at " ANSI_YELLOW "%s:%s" ANSI_NORMAL ":", pos.file, showErrPos(pos));
                 break;
             }
             case foString: {
-                out << prefix << ANSI_BLUE << "at: " << ANSI_YELLOW << showErrPos(pos) <<
-                    ANSI_BLUE << " from string" << ANSI_NORMAL;
+                out << fmt(ANSI_BLUE "at " ANSI_YELLOW "«string»:%s" ANSI_NORMAL ":", showErrPos(pos));
                 break;
             }
             case foStdin: {
-                out << prefix << ANSI_BLUE << "at: " << ANSI_YELLOW << showErrPos(pos) <<
-                    ANSI_BLUE << " from stdin" << ANSI_NORMAL;
+                out << fmt(ANSI_BLUE "at " ANSI_YELLOW "«stdin»:%s" ANSI_NORMAL ":", showErrPos(pos));
                 break;
             }
             default:
@@ -272,7 +268,7 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
 
     if (einfo.errPos.has_value() && *einfo.errPos) {
         oss << "\n";
-        printAtPos("", *einfo.errPos, oss);
+        printAtPos(*einfo.errPos, oss);
 
         auto loc = getCodeLines(*einfo.errPos);
 
@@ -292,7 +288,7 @@ std::ostream & showErrorInfo(std::ostream & out, const ErrorInfo & einfo, bool s
             if (iter->pos.has_value() && (*iter->pos)) {
                 auto pos = iter->pos.value();
                 oss << "\n";
-                printAtPos("", pos, oss);
+                printAtPos(pos, oss);
 
                 auto loc = getCodeLines(pos);
                 if (loc.has_value()) {
diff --git a/tests/misc.sh b/tests/misc.sh
index a81c9dbb1..2830856ae 100644
--- a/tests/misc.sh
+++ b/tests/misc.sh
@@ -17,10 +17,10 @@ nix-env -q --foo 2>&1 | grep "unknown flag"
 
 # Eval Errors.
 eval_arg_res=$(nix-instantiate --eval -E 'let a = {} // a; in a.foo' 2>&1 || true)
-echo $eval_arg_res | grep "at: (1:15) from string"
+echo $eval_arg_res | grep "at «string»:1:15:"
 echo $eval_arg_res | grep "infinite recursion encountered"
 
 eval_stdin_res=$(echo 'let a = {} // a; in a.foo' | nix-instantiate --eval -E - 2>&1 || true)
-echo $eval_stdin_res | grep "at: (1:15) from stdin"
+echo $eval_stdin_res | grep "at «stdin»:1:15:"
 echo $eval_stdin_res | grep "infinite recursion encountered"