internal/repotools: IsModuleChanged bugfix (#1342)

Author: skmcgrail

internal/repotools/gomod/diff.go

@@ -11,6 +11,10 @@ import (
 func IsModuleChanged(moduleDir string, submodules []string, changes []string) (bool, error) {
 	if moduleDir == "." {
 		moduleDir = ""
+	} else {
+		// Append the path separator to ensure it is used in prefix matches. This ensure that we are looking
+		// at this specific directory and children rather then any directory that has this moduleDir prefix.
+		moduleDir += "/"
 	}
 
 	isChildPathCache := make(map[string]bool)

internal/repotools/gomod/diff_test.go

@@ -91,6 +91,15 @@ func TestIsModuleChanged(t *testing.T) {
 			},
 			want: true,
 		},
+		"module with no changes, but shares common prefix with a changed module": {
+			moduleDir:  "foobar",
+			submodules: []string{"foobar/sub1"},
+			changes: []string{
+				"foobarbaz/baz.go",
+				"foobar/sub1/sub1.go",
+			},
+			want: false,
+		},
 	}
 	for name, tt := range tests {
 		t.Run(name, func(t *testing.T) {