backport of commit b366ff28ff

command/fmt_test.go

@@ -177,3 +177,18 @@ func Test_fmt_pipe(t *testing.T) {
 		})
 	}
 }
+
+const malformedTemplate = "test-fixtures/fmt_errs/malformed.pkr.hcl"
+
+func TestFmtParseError(t *testing.T) {
+	p := helperCommand(t, "fmt", malformedTemplate)
+	outs, err := p.CombinedOutput()
+	if err == nil {
+		t.Errorf("Expected failure to format file, but command did not fail")
+	}
+	strLogs := string(outs)
+
+	if !strings.Contains(strLogs, "An argument or block definition is required here.") {
+		t.Errorf("Expected some diags about parse error, found none")
+	}
+}

command/test-fixtures/fmt_errs/malformed.pkr.hcl

@@ -0,0 +1,14 @@
+variable "region" {
+  type =string
+}
+
+invalid
+
+source "amazon-ebs" "example" {
+  region = var.region
+}
+
+build {
+  sources = ["source.amazon-ebs.example"]
+}
+

hcl2template/formatter.go

@@ -12,6 +12,7 @@ import (
 	"path/filepath"
 	"strings"
 
+	"github.com/hashicorp/go-multierror"
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/hclparse"
 	"github.com/hashicorp/hcl/v2/hclwrite"
@@ -135,7 +136,7 @@ func (f *HCL2Formatter) processFile(filename string) ([]byte, error) {
 
 	_, diags := f.parser.ParseHCL(inSrc, filename)
 	if diags.HasErrors() {
-		return nil, fmt.Errorf("failed to parse HCL %s", filename)
+		return nil, multierror.Append(nil, diags.Errs()...)
 	}
 
 	outSrc := hclwrite.Format(inSrc)