feat(evaluator): Add API's for backwards compatibility

Ensure the previous change is backwards compatible.

Signed-off-by: Frank Viernau <frank.viernau@gmail.com>

Author: fviernau

evaluator/src/main/kotlin/PackageRule.kt

@@ -268,6 +268,16 @@ open class PackageRule(
             }
         }
 
+        /** Backwards compatibility */
+        @Suppress("unused") // This is intended to be used by rule implementations.
+        val licenseSource by lazy {
+            require(licenseSources.size == 1) {
+                "The license source is ambiguous. Please use the licenseSources property instead."
+            }
+
+            licenseSources.single()
+        }
+
         /**
          * A shortcut for the [license][ResolvedLicense.license] in [resolvedLicense].
          */

evaluator/src/main/kotlin/Rule.kt

@@ -197,3 +197,52 @@ abstract class Rule(
         }
     }
 }
+
+/**
+ * Backward compatibility for [Rule.issue()].
+ */
+@Suppress("unused") // This is intended to be used by rule implementations.
+fun Rule.issue(
+    severity: Severity,
+    pkgId: Identifier?,
+    license: SpdxSingleLicenseExpression?,
+    licenseSource: LicenseSource?,
+    message: String,
+    howToFix: String
+) = issue(severity, pkgId, license, setOfNotNull(licenseSource), message, howToFix)
+
+/**
+ * Backward compatibility for [Rule.hint()].
+ */
+@Suppress("unused") // This is intended to be used by rule implementations.
+fun Rule.hint(
+    pkgId: Identifier?,
+    license: SpdxSingleLicenseExpression?,
+    licenseSource: LicenseSource?,
+    message: String,
+    howToFix: String
+) = hint(pkgId, license, setOfNotNull(licenseSource), message, howToFix)
+
+/**
+ * Backward compatibility for [Rule.warning()].
+ */
+@Suppress("unused") // This is intended to be used by rule implementations.
+fun Rule.warning(
+    pkgId: Identifier?,
+    license: SpdxSingleLicenseExpression?,
+    licenseSource: LicenseSource?,
+    message: String,
+    howToFix: String
+) = warning(pkgId, license, setOfNotNull(licenseSource), message, howToFix)
+
+/**
+ * Backward compatibility for [Rule.error()].
+ */
+@Suppress("unused") // This is intended to be used by rule implementations.
+fun Rule.error(
+    pkgId: Identifier?,
+    license: SpdxSingleLicenseExpression?,
+    licenseSource: LicenseSource?,
+    message: String,
+    howToFix: String
+) = warning(pkgId, license, setOfNotNull(licenseSource), message, howToFix)