Update zip archive handling to match globs as expected (#244)

* Refactor zip file tests

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

* Add glob support for leading slashes

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

* Update zip testing to account for glob matching

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

* Ignore .DS_STORE

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

* Improve normalization of zip entry names

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

* Rename zip test helpers file

Signed-off-by: Dan Luhring <dan.luhring@anchore.com>

internal/file/zip_file_manifest_test.go

@@ -0,0 +1,109 @@
+package file
+
+import (
+	"encoding/json"
+	"os"
+	"path"
+	"testing"
+)
+
+func TestNewZipFileManifest(t *testing.T) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sourceDirPath := path.Join(cwd, "test-fixtures", "zip-source")
+	err = ensureNestedZipExists(t, sourceDirPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cleanup, archiveFilePath, err := setupZipFileTest(t, sourceDirPath)
+	defer fatalIfError(t, cleanup)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	actual, err := NewZipFileManifest(archiveFilePath)
+	if err != nil {
+		t.Fatalf("unable to extract from unzip archive: %+v", err)
+	}
+
+	if len(expectedZipArchiveEntries) != len(actual) {
+		t.Fatalf("mismatched manifest: %d != %d", len(actual), len(expectedZipArchiveEntries))
+	}
+
+	for _, e := range expectedZipArchiveEntries {
+		_, ok := actual[e]
+		if !ok {
+			t.Errorf("missing path: %s", e)
+		}
+	}
+
+	if t.Failed() {
+		b, err := json.MarshalIndent(actual, "", "  ")
+		if err != nil {
+			t.Fatalf("can't show results: %+v", err)
+		}
+
+		t.Errorf("full result: %s", string(b))
+	}
+}
+
+func TestZipFileManifest_GlobMatch(t *testing.T) {
+	cwd, err := os.Getwd()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	sourceDirPath := path.Join(cwd, "test-fixtures", "zip-source")
+	err = ensureNestedZipExists(t, sourceDirPath)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cleanup, archiveFilePath, err := setupZipFileTest(t, sourceDirPath)
+	//goland:noinspection GoNilness
+	defer fatalIfError(t, cleanup)
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	z, err := NewZipFileManifest(archiveFilePath)
+	if err != nil {
+		t.Fatalf("unable to extract from unzip archive: %+v", err)
+	}
+
+	cases := []struct {
+		glob     string
+		expected string
+	}{
+		{
+			"/b*",
+			"b-file.txt",
+		},
+		{
+			"*/a-file.txt",
+			"some-dir/a-file.txt",
+		},
+		{
+			"**/*.zip",
+			"nested.zip",
+		},
+	}
+
+	for _, tc := range cases {
+		t.Run(tc.glob, func(t *testing.T) {
+			glob := tc.glob
+
+			results := z.GlobMatch(glob)
+
+			if len(results) == 1 && results[0] == tc.expected {
+				return
+			}
+
+			t.Errorf("unexpected results for glob '%s': %+v", glob, results)
+		})
+	}
+}