Use same keys for system props and env vars

The previous mapping of env var keys to lowercase for system props
was at attempt to make build scripts look nicer, but violated the
principle of least surprise.

Author: bigdaz

README.md

@@ -38,19 +38,18 @@ The following environment variables configure the snapshot generated by the `Git
 - `DEPENDENCY_GRAPH_REPORT_DIR` (optional): Specifies where the dependency graph report will be generated
 
 Each of these values can also be provided via a system property. 
-The equivalent system property name is lower case, with '_' replaced by '-'. 
-eg: Env var `DEPENDENCY_GRAPH_REPORT_DIR` can be set as `-Ddependency-graph-report-dir=foo` on the command-line.
+eg: Env var `DEPENDENCY_GRAPH_REPORT_DIR` can be set with `-DDEPENDENCY_GRAPH_REPORT_DIR=...` on the command-line.
 
 ### Filtering which Gradle Configurations contribute to the dependency graph
 
 If you do not want to include every dependency configuration in every project in your build, you can limit the
 dependency extraction to a subset of these.
 
 To restrict which Gradle subprojects contribute to the report, specify which projects to include via a regular expression.
-You can provide this value via the `DEPENDENCY_GRAPH_INCLUDE_PROJECTS` environment variable, or the `dependency-graph-include-projects` System property.
+You can provide this value via the `DEPENDENCY_GRAPH_INCLUDE_PROJECTS` environment variable or system property.
 
 To restrict which Gradle configurations contribute to the report, you can filter configurations by name using a regular expression.
-You can provide this value via the `DEPENDENCY_GRAPH_INCLUDE_CONFIGURATIONS` environment variable, or the `dependency-graph-include-configurations` System property.
+You can provide this value via the `DEPENDENCY_GRAPH_INCLUDE_CONFIGURATIONS` environment variable or system property.
 
 ### Gradle compatibility
 

plugin-test/src/test/groovy/org/gradle/github/dependencygraph/DependencyExtractorConfigTest.groovy

@@ -38,8 +38,8 @@ class DependencyExtractorConfigTest extends BaseExtractorTest {
 
         when:
         executer
-            .withArgument("-Dgithub-job-correlator=TEST_CORRELATOR")
-            .withArgument("-Dgithub-ref=refs/my-branch/foo")
+            .withArgument("-DGITHUB_JOB_CORRELATOR=TEST_CORRELATOR")
+            .withArgument("-DGITHUB_REF=refs/my-branch/foo")
         run()
 
         then:

plugin-test/src/test/groovy/org/gradle/github/dependencygraph/MultiProjectDependencyExtractorTest.groovy

@@ -271,7 +271,7 @@ class MultiProjectDependencyExtractorTest extends BaseExtractorTest {
         """
 
         when:
-        executer.withArgument("-Ddependency-graph-include-projects=:b")
+        executer.withArgument("-DDEPENDENCY_GRAPH_INCLUDE_PROJECTS=:b")
         run()
 
         then:
@@ -304,7 +304,7 @@ class MultiProjectDependencyExtractorTest extends BaseExtractorTest {
         """
 
         when:
-        executer.withArgument("-Ddependency-graph-include-configurations=compileClasspath")
+        executer.withArgument("-DDEPENDENCY_GRAPH_INCLUDE_CONFIGURATIONS=compileClasspath")
         run()
 
         then:

plugin/src/main/kotlin/org/gradle/github/dependencygraph/internal/util/PluginParameters.kt

@@ -19,23 +19,19 @@ const val PARAM_GITHUB_WORKSPACE = "GITHUB_WORKSPACE"
 
 class PluginParameters {
     fun load(envName: String, default: String? = null): String {
-        return System.getProperty(sysPropName(envName))
+        return System.getProperty(envName)
             ?: System.getenv()[envName]
             ?: default
             ?: throwEnvironmentVariableMissingException(envName)
     }
 
     fun loadOptional(envName: String): String? {
-        return System.getProperty(sysPropName(envName))
+        return System.getProperty(envName)
             ?: System.getenv()[envName]
     }
 
-    private fun sysPropName(envName: String): String {
-        return envName.toLowerCase().replace('_', '-')
-    }
-
     private fun throwEnvironmentVariableMissingException(variable: String): Nothing {
         throw IllegalStateException("The configuration parameter '$variable' must be set: " +
-            "set an environment variable, or '-D${sysPropName(variable)}=value' on the command-line.")
+            "set an environment variable, or use '-D${variable}=value' on the command-line.")
     }
 }