feat: Add R cataloger (#1790)

Add a cataloger that detects installed R packages by looking for DESCRIPTION
files. The base R package is now picked up in coverageImage tests in
test/cli/packages_cmd_test.go, so increment expected package counts for the
tests that use that image.

Signed-off-by: Will Murphy <will.murphy@anchore.com>

test/integration/catalog_packages_cases_test.go

@@ -69,6 +69,14 @@ var imageOnlyTestCases = []testCase{
 			"joda-time":              "2.9.2",
 		},
 	},
+	{
+		name:        "find R packages",
+		pkgType:     pkg.Rpkg,
+		pkgLanguage: pkg.R,
+		pkgInfo: map[string]string{
+			"base": "4.3.0",
+		},
+	},
 }
 
 var dirOnlyTestCases = []testCase{

test/integration/catalog_packages_test.go

@@ -220,10 +220,12 @@ func TestPkgCoverageDirectory(t *testing.T) {
 
 	observedLanguages.Remove(pkg.UnknownLanguage.String())
 	definedLanguages.Remove(pkg.UnknownLanguage.String())
+	definedLanguages.Remove(pkg.R.String())
 	observedPkgs.Remove(string(pkg.UnknownPkg))
 	definedPkgs.Remove(string(pkg.BinaryPkg))
 	definedPkgs.Remove(string(pkg.LinuxKernelPkg))
 	definedPkgs.Remove(string(pkg.LinuxKernelModulePkg))
+	definedPkgs.Remove(string(pkg.Rpkg))
 	definedPkgs.Remove(string(pkg.UnknownPkg))
 
 	// for directory scans we should not expect to see any of the following package types

test/integration/test-fixtures/image-pkg-coverage/pkgs/r/base/DESCRIPTION

@@ -0,0 +1,11 @@
+Package: base
+Version: 4.3.0
+Priority: base
+Title: The R Base Package
+Author: R Core Team and contributors worldwide
+Maintainer: R Core Team <do-use-Contact-address@r-project.org>
+Contact: R-help mailing list <r-help@r-project.org>
+Description: Base R functions.
+License: Part of R 4.3.0
+Suggests: methods
+Built: R 4.3.0; ; 2023-04-21 11:33:09 UTC; unix