fix: allow missing go env vars

Signed-off-by: Ruben Romero Montes <rromerom@redhat.com>

Author: ruromero

src/main/java/com/redhat/exhort/providers/GoModulesProvider.java

@@ -40,6 +40,7 @@
 import java.util.List;
 import java.util.Map;
 import java.util.Objects;
+import java.util.Optional;
 import java.util.TreeMap;
 import java.util.logging.Logger;
 import java.util.regex.Pattern;
@@ -69,7 +70,7 @@ public String getMainModuleVersion() {
   public GoModulesProvider(Path manifest) {
     super(Type.GOLANG, manifest);
     this.goExecutable = Operations.getExecutable(GO_BINARY, "version");
-    this.goEnvironmentVariableForPurl = getQualifiers(true);
+    this.goEnvironmentVariableForPurl = getQualifiers();
     this.mainModuleVersion = getDefaultMainModuleVersion();
   }
 
@@ -379,26 +380,32 @@ private static List<String> collectAllDirectDependencies(List<String> targetLine
         .collect(Collectors.toList());
   }
 
-  private TreeMap<String, String> getQualifiers(boolean includeOsAndArch) {
-    if (includeOsAndArch) {
-      String goEnvironmentVariables = Operations.runProcessGetOutput(null, goExecutable, "env");
-      String hostArch =
-          getEnvironmentVariable(goEnvironmentVariables, GO_HOST_ARCHITECTURE_ENV_NAME);
-      String hostOS =
-          getEnvironmentVariable(goEnvironmentVariables, GO_HOST_OPERATION_SYSTEM_ENV_NAME);
-      return new TreeMap<>(Map.of("type", "module", "goos", hostOS, "goarch", hostArch));
+  private TreeMap<String, String> getQualifiers() {
+    String goEnvironmentVariables = Operations.runProcessGetOutput(null, goExecutable, "env");
+    var hostArch = getEnvironmentVariable(goEnvironmentVariables, GO_HOST_ARCHITECTURE_ENV_NAME);
+    var hostOS = getEnvironmentVariable(goEnvironmentVariables, GO_HOST_OPERATION_SYSTEM_ENV_NAME);
+    var qualifiers = new TreeMap<String, String>();
+    qualifiers.put("type", "module");
+    if (hostOS.isPresent()) {
+      qualifiers.put("goos", hostOS.get());
     }
-
-    return new TreeMap<>(Map.of("type", "module"));
+    if (hostArch.isPresent()) {
+      qualifiers.put("goarch", hostArch.get());
+    }
+    return qualifiers;
   }
 
-  private static String getEnvironmentVariable(String goEnvironmentVariables, String envName) {
+  private static Optional<String> getEnvironmentVariable(
+      String goEnvironmentVariables, String envName) {
     int i = goEnvironmentVariables.indexOf(String.format("%s=", envName));
+    if (i == -1) {
+      return Optional.empty();
+    }
     int beginIndex = i + String.format("%s=", envName).length();
     int endOfLineIndex =
         goEnvironmentVariables.substring(beginIndex).indexOf(System.lineSeparator());
     String envValue = goEnvironmentVariables.substring(beginIndex).substring(0, endOfLineIndex);
-    return envValue.replaceAll("\"", "");
+    return Optional.of(envValue.replaceAll("\"", ""));
   }
 
   private String buildGoModulesDependencies(Path manifestPath) {