port php cataloger to new generic cataloger pattern (#1315)

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

syft/pkg/cataloger/php/package_test.go

@@ -0,0 +1,53 @@
+package php
+
+import (
+	"testing"
+
+	"github.com/sergi/go-diff/diffmatchpatch"
+
+	"github.com/anchore/syft/syft/pkg"
+)
+
+func Test_packageURL(t *testing.T) {
+	tests := []struct {
+		name     string
+		metadata pkg.PhpComposerJSONMetadata
+		expected string
+	}{
+		{
+			name: "with extractable vendor",
+			metadata: pkg.PhpComposerJSONMetadata{
+				Name:    "ven/name",
+				Version: "1.0.1",
+			},
+			expected: "pkg:composer/ven/name@1.0.1",
+		},
+		{
+			name: "name with slashes (invalid)",
+			metadata: pkg.PhpComposerJSONMetadata{
+				Name:    "ven/name/component",
+				Version: "1.0.1",
+			},
+			expected: "pkg:composer/ven/name-component@1.0.1",
+		},
+		{
+			name: "unknown vendor",
+			metadata: pkg.PhpComposerJSONMetadata{
+				Name:    "name",
+				Version: "1.0.1",
+			},
+			expected: "pkg:composer/name@1.0.1",
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			actual := packageURL(test.metadata)
+			if actual != test.expected {
+				dmp := diffmatchpatch.New()
+				diffs := dmp.DiffMain(test.expected, actual, true)
+				t.Errorf("diff: %s", dmp.DiffPrettyText(diffs))
+			}
+		})
+	}
+}