Validate FHIRPath constraints in IGs and profiles

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/elementmodel/FmlParser.java

@@ -57,7 +57,7 @@ public class FmlParser extends ParserBase {
   }
 
   public Element parse(String text) throws FHIRException {
-    FHIRLexer lexer = new FHIRLexer(text, "source", true);
+    FHIRLexer lexer = new FHIRLexer(text, "source", true, true);
     if (lexer.done())
       throw lexer.error("Map Input cannot be empty");
     Element result = Manager.build(context, context.fetchTypeDefinition("StructureMap"));

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/FHIRLexer.java

@@ -88,6 +88,7 @@ public class FHIRLexer {
   private boolean liquidMode; // in liquid mode, || terminates the expression and hands the parser back to the host
   private SourceLocation commentLocation;
   private boolean metadataFormat;
+  private boolean allowDoubleQuotes;
 
   public FHIRLexer(String source, String name) throws FHIRLexerException {
     this.source = source == null ? "" : source;
@@ -101,10 +102,18 @@ public class FHIRLexer {
     currentLocation = new SourceLocation(1, 1);
     next();
   }
-  public FHIRLexer(String source, String name, boolean metadataFormat) throws FHIRLexerException {
+  public FHIRLexer(String source, int i, boolean allowDoubleQuotes) throws FHIRLexerException {
+    this.source = source;
+    this.cursor = i;
+    this.allowDoubleQuotes =  allowDoubleQuotes;
+    currentLocation = new SourceLocation(1, 1);
+    next();
+  }
+  public FHIRLexer(String source, String name, boolean metadataFormat, boolean allowDoubleQuotes) throws FHIRLexerException {
     this.source = source == null ? "" : source;
     this.name = name == null ? "??" : name;
     this.metadataFormat = metadataFormat;
+    this.allowDoubleQuotes =  allowDoubleQuotes;
     currentLocation = new SourceLocation(1, 1);
     next();
   }
@@ -235,7 +244,7 @@ public class FHIRLexer {
         if (ch == '}')
           cursor++;
         current = source.substring(currentStart, cursor);
-      } else if (ch == '"') {
+      } else if (ch == '"' && allowDoubleQuotes) {
         cursor++;
         boolean escape = false;
         while (cursor < source.length() && (escape || source.charAt(cursor) != '"')) {
@@ -588,5 +597,7 @@ public class FHIRLexer {
       return null;
     }
   }
-
+  public boolean isAllowDoubleQuotes() {
+    return allowDoubleQuotes;
+  }
 }

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/FHIRPathEngine.java

@@ -280,6 +280,7 @@ public class FHIRPathEngine {
   private boolean liquidMode; // in liquid mode, || terminates the expression and hands the parser back to the host
   private boolean doNotEnforceAsSingletonRule;
   private boolean doNotEnforceAsCaseSensitive;
+  private boolean allowDoubleQuotes;
 
   // if the fhir path expressions are allowed to use constants beyond those defined in the specification
   // the application can implement them by providing a constant resolver 
@@ -511,7 +512,7 @@ public class FHIRPathEngine {
   }
 
   public ExpressionNode parse(String path, String name) throws FHIRLexerException {
-    FHIRLexer lexer = new FHIRLexer(path, name);
+    FHIRLexer lexer = new FHIRLexer(path, name, false, allowDoubleQuotes);
     if (lexer.done()) {
       throw lexer.error("Path cannot be empty");
     }
@@ -548,7 +549,7 @@ public class FHIRPathEngine {
    * @throws Exception
    */
   public ExpressionNodeWithOffset parsePartial(String path, int i) throws FHIRLexerException {
-    FHIRLexer lexer = new FHIRLexer(path, i);
+    FHIRLexer lexer = new FHIRLexer(path, i, allowDoubleQuotes);
     if (lexer.done()) {
       throw lexer.error("Path cannot be empty");
     }
@@ -5816,7 +5817,11 @@ public class FHIRPathEngine {
       String tail = "";
       StructureDefinition sd = worker.fetchResource(StructureDefinition.class, url);
       if (sd == null) {
-        throw makeException(expr, I18nConstants.FHIRPATH_NO_TYPE, url, "getChildTypesByName");
+        if (url.startsWith(TypeDetails.FP_NS)) {
+          return;
+        } else {
+          throw makeException(expr, I18nConstants.FHIRPATH_UNKNOWN_TYPE, url, "getChildTypesByName");          
+        }
       }
       List<StructureDefinition> sdl = new ArrayList<StructureDefinition>();
       ElementDefinitionMatch m = null;
@@ -5826,14 +5831,14 @@ public class FHIRPathEngine {
         if (m.fixedType != null)  {
           StructureDefinition dt = worker.fetchResource(StructureDefinition.class, ProfileUtilities.sdNs(m.fixedType, null), sd);
           if (dt == null) {
-            throw makeException(expr, I18nConstants.FHIRPATH_NO_TYPE, ProfileUtilities.sdNs(m.fixedType, null), "getChildTypesByName");
+            throw makeException(expr, I18nConstants.FHIRPATH_UNKNOWN_TYPE, ProfileUtilities.sdNs(m.fixedType, null), "getChildTypesByName");
           }
           sdl.add(dt);
         } else
           for (TypeRefComponent t : m.definition.getType()) {
             StructureDefinition dt = worker.fetchResource(StructureDefinition.class, ProfileUtilities.sdNs(t.getCode(), null));
             if (dt == null) {
-              throw makeException(expr, I18nConstants.FHIRPATH_NO_TYPE, ProfileUtilities.sdNs(t.getCode(), null), "getChildTypesByName");
+              throw makeException(expr, I18nConstants.FHIRPATH_UNKNOWN_TYPE, ProfileUtilities.sdNs(t.getCode(), null), "getChildTypesByName");
             }
             addTypeAndDescendents(sdl, dt, cu.allStructures());
             // also add any descendant types
@@ -6392,4 +6397,10 @@ public class FHIRPathEngine {
     return profileUtilities;
   }
 
+  public boolean isAllowDoubleQuotes() {
+    return allowDoubleQuotes;
+  }
+  public void setAllowDoubleQuotes(boolean allowDoubleQuotes) {
+    this.allowDoubleQuotes = allowDoubleQuotes;    
+  }
 }

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/LiquidEngine.java

@@ -176,7 +176,7 @@ public class LiquidEngine implements IEvaluationContext {
     @Override
     public void evaluate(StringBuilder b, Base resource, LiquidEngineContext ctxt) throws FHIRException {
       if (compiled.size() == 0) {
-        FHIRLexer lexer = new FHIRLexer(statement, "liquid statement");
+        FHIRLexer lexer = new FHIRLexer(statement, "liquid statement", false, true);
         lexer.setLiquidMode(true);
         compiled.add(new LiquidExpressionNode(null, engine.parse(lexer)));
         while (!lexer.done()) {

org.hl7.fhir.r5/src/main/java/org/hl7/fhir/r5/utils/structuremap/StructureMapUtilities.java

@@ -626,7 +626,7 @@ public class StructureMapUtilities {
   }
 
   public StructureMap parse(String text, String srcName) throws FHIRException {
-    FHIRLexer lexer = new FHIRLexer(Utilities.stripBOM(text), srcName, true);
+    FHIRLexer lexer = new FHIRLexer(Utilities.stripBOM(text), srcName, true, true);
     if (lexer.done())
       throw lexer.error("Map Input cannot be empty");
     StructureMap result = new StructureMap();

org.hl7.fhir.r5/src/test/java/org/hl7/fhir/r5/context/BaseWorkerContextTests.java

@@ -3,6 +3,7 @@ package org.hl7.fhir.r5.context;
 import org.hl7.fhir.exceptions.FHIRException;
 import org.hl7.fhir.r5.model.PackageInformation;
 import org.hl7.fhir.r5.model.Parameters;
+import org.hl7.fhir.r5.model.Resource;
 import org.hl7.fhir.r5.model.ValueSet;
 import org.hl7.fhir.r5.utils.validation.IResourceValidator;
 import org.hl7.fhir.utilities.npm.BasePackageCacheManager;
@@ -75,6 +76,11 @@ public class BaseWorkerContextTests {
       public String getSpecUrl() {
         return null;
       }
+
+      @Override
+      public <T extends Resource> T fetchResourceRaw(Class<T> class_, String uri) {
+        return null;
+      }
     };
     baseWorkerContext.expParameters = new Parameters();
     return baseWorkerContext;

org.hl7.fhir.r5/src/test/java/org/hl7/fhir/r5/utils/FHIRLexerTest.java

@@ -8,7 +8,7 @@ class FHIRLexerTest {
   @Test
   @DisplayName("Test that a 'null' current value returns 'false' when FHIRLexer.isConstant() is called, and not NPE.")
   void getCurrent() {
-    FHIRLexer lexer = new FHIRLexer(null, null);
+    FHIRLexer lexer = new FHIRLexer(null, null, false, true);
     String lexerCurrent = lexer.getCurrent();
     Assertions.assertNull(lexerCurrent);
     Assertions.assertFalse(lexer.isConstant());

org.hl7.fhir.utilities/src/main/java/org/hl7/fhir/utilities/SimpleHTTPClient.java

@@ -163,9 +163,11 @@ public class SimpleHTTPClient {
   }
 
   private void setHeaders(HttpURLConnection c) {
+    if (headers != null) {
       for (Header h : headers) {
         c.setRequestProperty(h.getName(), h.getValue());        
       }
+    }
     c.setConnectTimeout(15000);
     c.setReadTimeout(15000);
     if (username != null) {

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/InstanceValidator.java

@@ -466,7 +466,7 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   private boolean noUnicodeBiDiControlChars;
   private HtmlInMarkdownCheck htmlInMarkdownCheck;
   private boolean allowComments;
-  private boolean displayWarnings;
+  private boolean allowDoubleQuotesInFHIRPath;
  
   private List<ImplementationGuide> igs = new ArrayList<>();
   private List<String> extensionDomains = new ArrayList<String>();
@@ -518,6 +518,7 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
       fpe.setLegacyMode(true);
     source = Source.InstanceValidator;
     fpe.setDoNotEnforceAsSingletonRule(!VersionUtilities.isR5VerOrLater(theContext.getVersion()));
+    fpe.setAllowDoubleQuotes(allowDoubleQuotesInFHIRPath);
   }
 
   @Override
@@ -2036,12 +2037,11 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
         }
       } else if (ctxt.getType() == ExtensionContextType.EXTENSION) {
         contexts.append("x:" + ctxt.getExpression());
-        NodeStack estack = stack.getParent();
+        String ext = stack.getElement().getNamedChildValue("url");
-        if (estack != null && estack.getElement().fhirType().equals("Extension")) {
-          String ext = estack.getElement().getNamedChildValue("url");
         if (ctxt.getExpression().equals(ext)) {
           ok = true;
-          }
+        } else {
+          plist.add(ext);
         }
       } else if (ctxt.getType() == ExtensionContextType.FHIRPATH) {
         contexts.append("p:" + ctxt.getExpression());
@@ -6490,6 +6490,14 @@ public class InstanceValidator extends BaseValidator implements IResourceValidat
   }
 
  
+  public boolean isAllowDoubleQuotesInFHIRPath() {
+    return allowDoubleQuotesInFHIRPath;
+  }
+
+  public void setAllowDoubleQuotesInFHIRPath(boolean allowDoubleQuotesInFHIRPath) {
+    this.allowDoubleQuotesInFHIRPath = allowDoubleQuotesInFHIRPath;
+  }
+
   public static void setParents(Element element) {
     if (element != null && !element.hasParentForValidator()) {
       element.setParentForValidator(null);

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/instance/type/StructureDefinitionValidator.java

@@ -5,7 +5,9 @@ import java.io.IOException;
 import java.util.ArrayList;
 import java.util.Comparator;
 import java.util.HashSet;
+import java.util.HashMap;
 import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 import org.hl7.fhir.convertors.factory.VersionConvertorFactory_10_50;
@@ -129,10 +131,10 @@ public class StructureDefinitionValidator extends BaseValidator {
       boolean logical = "logical".equals(src.getNamedChildValue("kind"));
       boolean constraint = "constraint".equals(src.getNamedChildValue("derivation"));
       for (Element differential : differentials) {
-        ok = validateElementList(errors, differential, stack.push(differential, -1, null, null), false, snapshots.size() > 0, sd, typeName, logical, constraint) && ok;
+        ok = validateElementList(errors, differential, stack.push(differential, -1, null, null), false, snapshots.size() > 0, sd, typeName, logical, constraint, src.getNamedChildValue("type"), src.getNamedChildValue("url")) && ok;
       }
       for (Element snapshotE : snapshots) {
-        ok = validateElementList(errors, snapshotE, stack.push(snapshotE, -1, null, null), true, true, sd, typeName, logical, constraint) && ok;
+        ok = validateElementList(errors, snapshotE, stack.push(snapshotE, -1, null, null), true, true, sd, typeName, logical, constraint, src.getNamedChildValue("type"), src.getNamedChildValue("url")) && ok;
       }
       
       // obligation profile support
@@ -330,18 +332,19 @@ public class StructureDefinitionValidator extends BaseValidator {
     }
   }
 
-  private boolean validateElementList(List<ValidationMessage> errors, Element elementList, NodeStack stack, boolean snapshot, boolean hasSnapshot, StructureDefinition sd, String typeName, boolean logical, boolean constraint) {
+  private boolean validateElementList(List<ValidationMessage> errors, Element elementList, NodeStack stack, boolean snapshot, boolean hasSnapshot, StructureDefinition sd, String typeName, boolean logical, boolean constraint, String rootPath, String profileUrl) {
+    Map<String, String> invariantMap = new HashMap<>();
     boolean ok = true;
     List<Element> elements = elementList.getChildrenByName("element");
     int cc = 0;
     for (Element element : elements) {
-      ok = validateElementDefinition(errors, element, stack.push(element, cc, null, null), snapshot, hasSnapshot, sd, typeName, logical, constraint) && ok;
+      ok = validateElementDefinition(errors, element, stack.push(element, cc, null, null), snapshot, hasSnapshot, sd, typeName, logical, constraint, invariantMap, rootPath, profileUrl) && ok;
       cc++;
     }    
     return ok;
   }
 
-  private boolean validateElementDefinition(List<ValidationMessage> errors, Element element, NodeStack stack, boolean snapshot, boolean hasSnapshot, StructureDefinition sd, String typeName, boolean logical, boolean constraint) {
+  private boolean validateElementDefinition(List<ValidationMessage> errors, Element element, NodeStack stack, boolean snapshot, boolean hasSnapshot, StructureDefinition sd, String typeName, boolean logical, boolean constraint, Map<String, String> invariantMap, String rootPath, String profileUrl) {
     boolean ok = true;
     boolean typeMustSupport = false;
     String path = element.getNamedChildValue("path");
@@ -466,6 +469,37 @@ public class StructureDefinitionValidator extends BaseValidator {
       }
       // if we see fixed[x] or pattern[x] applied to a repeating element, we'll give the user a hint
     }
+    List<Element> constraints = element.getChildrenByName("constraint");
+    int cc = 0;
+    for (Element invariant : constraints) {
+      ok = validateElementDefinitionInvariant(errors, invariant, stack.push(invariant, cc, null, null), invariantMap, element.getNamedChildValue("path"), rootPath, profileUrl) && ok;
+      cc++;
+    }    
+    return ok;
+  }
+  
+  private boolean validateElementDefinitionInvariant(List<ValidationMessage> errors, Element invariant, NodeStack stack, Map<String, String> invariantMap, String path, String rootPath, String profileUrl) {
+    boolean ok = true;
+    String key = invariant.getNamedChildValue("key"); 
+    String expression = invariant.getNamedChildValue("expression");
+    String source = invariant.getNamedChildValue("source");
+    if (warning(errors, "2023-06-19", IssueType.INFORMATIONAL, stack, !Utilities.noString(key), I18nConstants.ED_INVARIANT_NO_KEY)) {
+      if (hint(errors, "2023-06-19", IssueType.INFORMATIONAL, stack, !Utilities.noString(expression), I18nConstants.ED_INVARIANT_NO_EXPRESSION, key)) {
+        if (invariantMap.containsKey(key)) {
+          // it's legal - and common - for a list of elemnts to contain the same invariant more than once, but it's not valid if it's not always the same 
+          ok = rule(errors, "2023-06-19", IssueType.INVALID, stack, expression.equals(invariantMap.get(key)), I18nConstants.ED_INVARIANT_EXPRESSION_CONFLICT, key, expression, invariantMap.get(key));
+        } else {
+          invariantMap.put(key, expression);
+        }
+        if (Utilities.noString(source) || (source.equals(profileUrl))) { // no need to revalidate FHIRPath from elsewhere 
+         try {
+           fpe.check(invariant, rootPath, path, fpe.parse(expression));
+         } catch (Exception e) {
+           ok = rule(errors, "2023-06-19", IssueType.INVALID, stack, false, I18nConstants.ED_INVARIANT_EXPRESSION_ERROR, key, expression, e.getMessage()) && ok;
+         }         
+        }        
+      }
+    }
     return ok;
   }
 

org.hl7.fhir.validation/src/main/java/org/hl7/fhir/validation/profile/ProfileValidator.java

@@ -51,11 +51,13 @@ public class ProfileValidator extends BaseValidator {
 
   private boolean checkAggregation = false;
   private boolean checkMustSupport = false;
+  private boolean allowDoubleQuotesInFHIRPath = false;
   private FHIRPathEngine fpe;
 
   public ProfileValidator(IWorkerContext context, XVerExtensionManager xverManager) {
     super(context, xverManager);
     fpe = new FHIRPathEngine(context);
+    fpe.setAllowDoubleQuotes(allowDoubleQuotesInFHIRPath);
   }
 
   public boolean isCheckAggregation() {
@@ -74,6 +76,14 @@ public class ProfileValidator extends BaseValidator {
     this.checkMustSupport = checkMustSupport;
   }
 
+  public boolean isAllowDoubleQuotesInFHIRPath() {
+    return allowDoubleQuotesInFHIRPath;
+  }
+
+  public void setAllowDoubleQuotesInFHIRPath(boolean allowDoubleQuotesInFHIRPath) {
+    this.allowDoubleQuotesInFHIRPath = allowDoubleQuotesInFHIRPath;
+  }
+
   protected boolean rule(List<ValidationMessage> errors, IssueType type, String path, boolean b, String msg) {
     String rn = path.contains(".") ? path.substring(0, path.indexOf(".")) : path;
     return super.ruleHtml(errors, NO_RULE_DATE, type, path, b, msg, "<a href=\""+(rn.toLowerCase())+".html\">"+rn+"</a>: "+Utilities.escapeXml(msg));