Allow for cataloging a single file (#608)

* allow for cataloging a single file

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

* use all catalogers for file schemes

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

test/cli/packages_cmd_test.go

@@ -130,6 +130,16 @@ func TestPackagesCmdFlags(t *testing.T) {
 				assertFailingReturnCode, // upload can't go anywhere, so if this passes that would be surprising
 			},
 		},
+		{
+			// we want to make certain that syft can catalog a single go binary and get a SBOM report that is not empty
+			name: "catalog-single-go-binary",
+			args: []string{"packages", "-o", "json", getSyftBinaryLocation(t)},
+			assertions: []traitAssertion{
+				assertJsonReport,
+				assertStdoutLengthGreaterThan(1000),
+				assertSuccessfulReturnCode,
+			},
+		},
 	}
 
 	for _, test := range tests {

test/cli/trait_assertions_test.go

@@ -75,6 +75,16 @@ func assertInOutput(data string) traitAssertion {
 	}
 }
 
+func assertStdoutLengthGreaterThan(length uint) traitAssertion {
+	return func(tb testing.TB, stdout, _ string, _ int) {
+		tb.Helper()
+		if uint(len(stdout)) < length {
+			tb.Errorf("not enough output (expected at least %d, got %d)", length, len(stdout))
+
+		}
+	}
+}
+
 func assertFailingReturnCode(tb testing.TB, _, _ string, rc int) {
 	tb.Helper()
 	if rc == 0 {