cmd/cue: print paths relative to the current directory in fmt --check

Fixes a bug introduced in https://cuelang.org/cl/1191220 where badly formatted paths
were printed relative to the cue module root instead of
the current working directory.

Signed-off-by: Noam Dolovich <[email protected]>
Change-Id: I70d258bff20175059117a6301ef9d8b01391b60a
Reviewed-on: https://review.gerrithub.io/c/cue-lang/cue/+/1191475
Reviewed-by: Daniel Martí <[email protected]>
TryBot-Result: CUEcueckoo <[email protected]>
Unity-Result: CUE porcuepine <[email protected]>

cmd/cue/cmd/fmt.go

@@ -18,6 +18,7 @@ import (
 	"bytes"
 	"fmt"
 	"os"
+	"path/filepath"
 
 	"cuelang.org/go/cue/ast"
 	"cuelang.org/go/cue/build"
@@ -121,17 +122,24 @@ func newFmtCmd(c *Command) *cobra.Command {
 					}
 
 					if check && !bytes.Equal(formatted.Bytes(), original) {
-						badlyFormattedFiles = append(badlyFormattedFiles, inst.RelPath(file))
+						badlyFormattedFiles = append(badlyFormattedFiles, file.Filename)
 					}
 				}
 			}
 
 			if check && len(badlyFormattedFiles) > 0 {
+				cwd, _ := os.Getwd()
 				stdout := cmd.OutOrStdout()
 				for _, f := range badlyFormattedFiles {
-					if f != "-" {
-						fmt.Fprintln(stdout, f)
+					if f == "-" {
+						continue
+					}
+
+					relPath, err := filepath.Rel(cwd, f)
+					if err != nil {
+						relPath = f
 					}
+					fmt.Fprintln(stdout, relPath)
 				}
 				os.Exit(1)
 			}

cmd/cue/cmd/testdata/script/fmt_check.txtar

@@ -1,3 +1,5 @@
+cd standalone
+
 # succeeds when file is formatted
 exec cue fmt --check formatted.cue
 
@@ -18,13 +20,30 @@ stdin not_formatted.cue
 ! exec cue fmt --check -
 ! stdout .
 
--- formatted.cue --
+cd ../module
+
+# files are printed relative to CWD
+! exec cue fmt --check ./...
+cmpenv stdout stdout.golden
+cd example
+! exec cue fmt --check ./...
+cmp stdout stdout.golden
+
+-- standalone/formatted.cue --
 foo: "bar"
--- not_formatted.cue --
+-- standalone/not_formatted.cue --
 foo:      "bar"
--- another/not_formatted.cue --
+-- standalone/another/not_formatted.cue --
 bar:   "baz"
 x:   1
--- expected-output --
+-- standalone/expected-output --
 not_formatted.cue
 another${/}not_formatted.cue
+-- module/cue.mod/module.cue --
+module: "example.com"
+-- module/stdout.golden --
+example${/}not_formatted.cue
+-- module/example/not_formatted.cue --
+foo:      "bar"
+-- module/example/stdout.golden --
+not_formatted.cue