FI-1223: Expose multiple software versions at /version endpoint (#62)

* starting point from #42

* FI-1223 refactor /version to return a JSON

* FI-1223: update api doc with new description of /version

* remove redundant function

rest-api.md

@@ -61,6 +61,17 @@ Also note that the request must have the `Content-Encoding: gzip` header.
 - **Response:**
 the NPM ID, version, and list of profile URLs of the loaded IG. [See here](#loading-a-custom-ig) for an example.
 
+### Get this wrapper's version
+- **Route:**
+`GET /version`
+- **Response:**
+A JSON object containing identifiers and version numbers for the software in use, such as the version of the wrapper itself and the version of the HL7 validator.
+- **Example Response:**
+```
+{"org.hl7.fhir.validation":"5.6.93","inferno-framework/fhir-validator-wrapper":"2.2.1"}
+```
+
+
 # FHIRPath Routes
 
 ### Evaluate a FHIRPath expression

src/main/java/org/mitre/inferno/Validator.java

@@ -305,10 +305,6 @@ public Map<String, List<String>> getProfilesByIg() {
         ));
   }
 
-  public String getVersion() {
-    return VersionUtil.getVersion();
-  }
-
   /**
    * Load a profile from a file.
    *

src/main/java/org/mitre/inferno/rest/ValidatorEndpoint.java

@@ -7,11 +7,13 @@
 
 import java.util.ArrayList;
 import java.util.Arrays;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
+
 import org.hl7.fhir.r5.formats.JsonParser;
 import org.hl7.fhir.r5.model.OperationOutcome;
 import org.mitre.inferno.Validator;
-import org.mitre.inferno.Version;
 
 public class ValidatorEndpoint {
   private static ValidatorEndpoint validatorEndpoint = null;
@@ -65,7 +67,7 @@ private void createRoutes() {
         (req, res) -> validator.loadIg(req.params("id"), req.queryParams("version")),
         TO_JSON);
 
-    get("/version", (req, res) -> Version.getVersion());
+    get("/version", (req, res) -> buildVersionResponse(), TO_JSON);
   }
 
   /**
@@ -87,4 +89,21 @@ private String validateResource(byte[] resource, String profile) throws Exceptio
     OperationOutcome oo = validator.validate(resource, patientProfiles);
     return new JsonParser().composeString(oo);
   }
+
+  /**
+   * Build a Map of the library versions used by this validator.
+   *
+   * @return a Map of library identifier -> version string
+   */
+  private Map<String,String> buildVersionResponse() {
+    // full package names used here only to make it more obvious what's going on
+    // since the class names aren't distinct enough
+    String hl7ValidatorVersion = org.hl7.fhir.validation.cli.utils.VersionUtil.getVersion();
+    String wrapperVersion = org.mitre.inferno.Version.getVersion();
+
+    Map<String, String> versions = new HashMap<>();
+    versions.put("org.hl7.fhir.validation", hl7ValidatorVersion);
+    versions.put("inferno-framework/fhir-validator-wrapper", wrapperVersion);
+    return versions;
+  }
 }