From 824bf244453bdb0502fa30de70c799d666665480 Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Fri, 12 Jul 2024 18:35:54 +0200
Subject: [PATCH] diagnostics: sort package diagnostics by position

Previously, the error messages could be shown out of order.
With this patch, the errors are sorted before being shown to the user.
This makes it easier to read the error messages, and matches what the
`go` toolchain does.
---
 diagnostics/diagnostics.go | 17 ++++++++++++++++-
 testdata/errors/types.go   |  2 +-
 2 files changed, 17 insertions(+), 2 deletions(-)

diff --git a/diagnostics/diagnostics.go b/diagnostics/diagnostics.go
index c793ba4aa6..f9261e2923 100644
--- a/diagnostics/diagnostics.go
+++ b/diagnostics/diagnostics.go
@@ -10,6 +10,7 @@ import (
 	"go/types"
 	"io"
 	"path/filepath"
+	"sort"
 	"strings"
 
 	"github.com/tinygo-org/tinygo/builder"
@@ -59,6 +60,7 @@ func CreateDiagnostics(err error) ProgramDiagnostic {
 // Create diagnostics for a single package (though, in practice, it may also be
 // used for whole-program diagnostics in some cases).
 func createPackageDiagnostic(err error) PackageDiagnostic {
+	// Extract diagnostics for this package.
 	var pkgDiag PackageDiagnostic
 	switch err := err.(type) {
 	case loader.Errors:
@@ -89,7 +91,20 @@ func createPackageDiagnostic(err error) PackageDiagnostic {
 	default:
 		pkgDiag.Diagnostics = createDiagnostics(err)
 	}
-	// TODO: sort
+
+	// Sort these diagnostics by file/line/column.
+	sort.SliceStable(pkgDiag.Diagnostics, func(i, j int) bool {
+		posI := pkgDiag.Diagnostics[i].Pos
+		posJ := pkgDiag.Diagnostics[j].Pos
+		if posI.Filename != posJ.Filename {
+			return posI.Filename < posJ.Filename
+		}
+		if posI.Line != posJ.Line {
+			return posI.Line < posJ.Line
+		}
+		return posI.Column < posJ.Column
+	})
+
 	return pkgDiag
 }
 
diff --git a/testdata/errors/types.go b/testdata/errors/types.go
index 491e2fe67a..6bd949f0c4 100644
--- a/testdata/errors/types.go
+++ b/testdata/errors/types.go
@@ -7,6 +7,6 @@ func main() {
 }
 
 // ERROR: # command-line-arguments
+// ERROR: types.go:4:6: a declared and not used
 // ERROR: types.go:5:6: cannot use "foobar" (untyped string constant) as int value in assignment
 // ERROR: types.go:6:2: undefined: nonexisting
-// ERROR: types.go:4:6: a declared and not used