Reworded documentation, fixed multiple targets to 1 existing file bug…

…, added a testcase for it.

docs/types.md

@@ -785,8 +785,8 @@ All types of FileSpecs share some common fields:
 
 A FileSpec with `type` equal to `path` points to an absolute or relative path accessible from the current machine.
 The path may also include a glob pattern to target multiple files or directories.
-For glob patterns resolving to multiple files, files will be copied into the specified `dest`.
-If `dest` does not exist, it will be automatically created.
+For paths that match multiple dirents, the dirents will be copied into `dest`.
+If `dest` does not exist, it will be automatically created as a directory.
 When a relative path is specified, additional context is required to know the relative base.
 For example, a FileSpec in an assignment config is relative to the assignment directory (the directory where the `assignment.json` file lives).
 

internal/common/filespec.go

@@ -225,7 +225,7 @@ func (this *FileSpec) CopyTarget(baseDir string, destDir string, onlyContents bo
 		// no-op.
 		return nil
 	case FILESPEC_TYPE_PATH:
-		return this.matchAndCopyPaths(baseDir, destDir, onlyContents)
+		return this.copyPaths(baseDir, destDir, onlyContents)
 	case FILESPEC_TYPE_GIT:
 		return this.copyGit(destDir)
 	case FILESPEC_TYPE_URL:
@@ -235,7 +235,7 @@ func (this *FileSpec) CopyTarget(baseDir string, destDir string, onlyContents bo
 	}
 }
 
-func (this *FileSpec) matchAndCopyPaths(baseDir string, destDir string, onlyContents bool) error {
+func (this *FileSpec) copyPaths(baseDir string, destDir string, onlyContents bool) error {
 	if !this.IsPath() {
 		return fmt.Errorf("Cannot match targets: FileSpec must be a path.")
 	}
@@ -270,7 +270,10 @@ func (this *FileSpec) matchAndCopyPaths(baseDir string, destDir string, onlyCont
 		return fmt.Errorf("No targets found for the path '%s'.", this.Path)
 	}
 
-	// Create a new directory if multiple paths are matched.
+	if util.IsFile(destPath) && len(paths) > 1 {
+		return fmt.Errorf("Cannot copy multiple targets into the existing file '%s'.", destDir)
+	}
+
 	if !util.PathExists(destPath) && len(paths) > 1 {
 		err := util.MkDir(destPath)
 		if err != nil {

internal/common/filespec_test.go

@@ -69,6 +69,7 @@ type testCaseCopy struct {
 	Spec                  FileSpec
 	OnlyContents          bool
 	ExpectedCopiedDirents []string
+	ExpectErrorForSameDir bool
 }
 
 func TestFileSpecCopy(test *testing.T) {
@@ -88,10 +89,20 @@ func TestFileSpecCopy(test *testing.T) {
 
 		destDir := filepath.Join(tempDir, "dest")
 
+		if testCase.ExpectErrorForSameDir {
+			destDir = filepath.Dir(testCase.Spec.Path)
+		}
+
 		err = testCase.Spec.CopyTarget(config.GetTestdataDir(), destDir, testCase.OnlyContents)
-		if err != nil {
+		if (!testCase.ExpectErrorForSameDir) && (err != nil) {
 			test.Errorf("Case %d: Failed to copy matching targets (%+v): '%v'.", i, testCase.Spec, err)
 			continue
+		} else if (testCase.ExpectErrorForSameDir) && (err == nil) {
+			test.Errorf("Case %d: Unexpectedly copied targets (%+v).", i, testCase.Spec)
+		}
+
+		if testCase.ExpectErrorForSameDir {
+			continue
 		}
 
 		dirents, err := util.GetAllDirents(destDir)
@@ -170,6 +181,11 @@ func getCopyTestCases() []*testCaseCopy {
 			Spec:                  FileSpec{Type: "path", Path: filepath.Join(config.GetTestdataDir(), "files", "filespec_test", "*"), Dest: "test"},
 			ExpectedCopiedDirents: []string{"test", "test/spec.txt", "test/spec2.txt"},
 		},
+		&testCaseCopy{
+			Spec:                  FileSpec{Type: "path", Path: filepath.Join(config.GetTestdataDir(), "files", "filespec_test", "*"), Dest: "spec.txt"},
+			OnlyContents:          true,
+			ExpectErrorForSameDir: true,
+		},
 		&testCaseCopy{
 			Spec:                  FileSpec{Type: "path", Path: filepath.Join(config.GetTestdataDir(), "files", "filespec_test", "*.txt"), Dest: "test"},
 			ExpectedCopiedDirents: []string{"test", "test/spec.txt", "test/spec2.txt"},