add support for exclusion rules in dockerignore

Signed-off-by: Dave Goodchild <buddhamagnet@gmail.com>

fileutils/fileutils_test.go

@@ -79,3 +79,142 @@ func TestReadSymlinkedDirectoryToFile(t *testing.T) {
 		t.Errorf("failed to remove symlink: %s", err)
 	}
 }
+
+func TestWildcardMatches(t *testing.T) {
+	match, _ := Matches("fileutils.go", []string{"*"})
+	if match != true {
+		t.Errorf("failed to get a wildcard match, got %v", match)
+	}
+}
+
+// A simple pattern match should return true.
+func TestPatternMatches(t *testing.T) {
+	match, _ := Matches("fileutils.go", []string{"*.go"})
+	if match != true {
+		t.Errorf("failed to get a match, got %v", match)
+	}
+}
+
+// An exclusion followed by an inclusion should return true.
+func TestExclusionPatternMatchesPatternBefore(t *testing.T) {
+	match, _ := Matches("fileutils.go", []string{"!fileutils.go", "*.go"})
+	if match != true {
+		t.Errorf("failed to get true match on exclusion pattern, got %v", match)
+	}
+}
+
+// A folder pattern followed by an exception should return false.
+func TestPatternMatchesFolderExclusions(t *testing.T) {
+	match, _ := Matches("docs/README.md", []string{"docs", "!docs/README.md"})
+	if match != false {
+		t.Errorf("failed to get a false match on exclusion pattern, got %v", match)
+	}
+}
+
+// A folder pattern followed by an exception should return false.
+func TestPatternMatchesFolderWithSlashExclusions(t *testing.T) {
+	match, _ := Matches("docs/README.md", []string{"docs/", "!docs/README.md"})
+	if match != false {
+		t.Errorf("failed to get a false match on exclusion pattern, got %v", match)
+	}
+}
+
+// A folder pattern followed by an exception should return false.
+func TestPatternMatchesFolderWildcardExclusions(t *testing.T) {
+	match, _ := Matches("docs/README.md", []string{"docs/*", "!docs/README.md"})
+	if match != false {
+		t.Errorf("failed to get a false match on exclusion pattern, got %v", match)
+	}
+}
+
+// A pattern followed by an exclusion should return false.
+func TestExclusionPatternMatchesPatternAfter(t *testing.T) {
+	match, _ := Matches("fileutils.go", []string{"*.go", "!fileutils.go"})
+	if match != false {
+		t.Errorf("failed to get false match on exclusion pattern, got %v", match)
+	}
+}
+
+// A filename evaluating to . should return false.
+func TestExclusionPatternMatchesWholeDirectory(t *testing.T) {
+	match, _ := Matches(".", []string{"*.go"})
+	if match != false {
+		t.Errorf("failed to get false match on ., got %v", match)
+	}
+}
+
+// A single ! pattern should return an error.
+func TestSingleExclamationError(t *testing.T) {
+	_, err := Matches("fileutils.go", []string{"!"})
+	if err == nil {
+		t.Errorf("failed to get an error for a single exclamation point, got %v", err)
+	}
+}
+
+// A string preceded with a ! should return true from Exclusion.
+func TestExclusion(t *testing.T) {
+	exclusion := Exclusion("!")
+	if !exclusion {
+		t.Errorf("failed to get true for a single !, got %v", exclusion)
+	}
+}
+
+// An empty string should return true from Empty.
+func TestEmpty(t *testing.T) {
+	empty := Empty("")
+	if !empty {
+		t.Errorf("failed to get true for an empty string, got %v", empty)
+	}
+}
+
+func TestCleanPatterns(t *testing.T) {
+	cleaned, _, _, _ := CleanPatterns([]string{"docs", "config"})
+	if len(cleaned) != 2 {
+		t.Errorf("expected 2 element slice, got %v", len(cleaned))
+	}
+}
+
+func TestCleanPatternsStripEmptyPatterns(t *testing.T) {
+	cleaned, _, _, _ := CleanPatterns([]string{"docs", "config", ""})
+	if len(cleaned) != 2 {
+		t.Errorf("expected 2 element slice, got %v", len(cleaned))
+	}
+}
+
+func TestCleanPatternsExceptionFlag(t *testing.T) {
+	_, _, exceptions, _ := CleanPatterns([]string{"docs", "!docs/README.md"})
+	if !exceptions {
+		t.Errorf("expected exceptions to be true, got %v", exceptions)
+	}
+}
+
+func TestCleanPatternsLeadingSpaceTrimmed(t *testing.T) {
+	_, _, exceptions, _ := CleanPatterns([]string{"docs", "  !docs/README.md"})
+	if !exceptions {
+		t.Errorf("expected exceptions to be true, got %v", exceptions)
+	}
+}
+
+func TestCleanPatternsTrailingSpaceTrimmed(t *testing.T) {
+	_, _, exceptions, _ := CleanPatterns([]string{"docs", "!docs/README.md  "})
+	if !exceptions {
+		t.Errorf("expected exceptions to be true, got %v", exceptions)
+	}
+}
+
+func TestCleanPatternsErrorSingleException(t *testing.T) {
+	_, _, _, err := CleanPatterns([]string{"!"})
+	if err == nil {
+		t.Errorf("expected error on single exclamation point, got %v", err)
+	}
+}
+
+func TestCleanPatternsFolderSplit(t *testing.T) {
+	_, dirs, _, _ := CleanPatterns([]string{"docs/config/CONFIG.md"})
+	if dirs[0][0] != "docs" {
+		t.Errorf("expected first element in dirs slice to be docs, got %v", dirs[0][1])
+	}
+	if dirs[0][1] != "config" {
+		t.Errorf("expected first element in dirs slice to be config, got %v", dirs[0][1])
+	}
+}