Diagnostics#actions

**Problem**
We want to pass along code actions via Diagnostics,
even though this idea seems to have been shot down already in LSP
microsoft/language-server-protocol 581.

**Solution**
This defines additional `actions` field to `Diagnostics`, mirroring
sbt/sbt#7242.

bsp4j/src/main/java/ch/epfl/scala/bsp4j/Protocol.xtend

@@ -244,6 +244,34 @@ class DiagnosticRelatedInformation {
   }
 }
 
+@JsonRpcData
+class CodeAction {
+  @NonNull String title
+  String description
+  WorkspaceEdit edit
+  new(@NonNull String title) {
+    this.title = title
+  }
+}
+
+@JsonRpcData
+class WorkspaceEdit {
+  List<TextEdit> changes
+  new(List<TextEdit> changes) {
+    this.changes = changes
+  }
+}
+
+@JsonRpcData
+class TextEdit {
+  @NonNull Range range
+  @NonNull String newText
+  new(@NonNull Range range, @NonNull String newText) {
+    this.range = range
+    this.newText = newText
+  }
+}
+
 @JsonRpcData
 class Diagnostic {
   @NonNull Range range
@@ -254,6 +282,7 @@ class Diagnostic {
   List<DiagnosticRelatedInformation> relatedInformation
   String dataKind
   @JsonAdapter(JsonElementTypeAdapter.Factory) Object data
+  List<CodeAction> actions
   new(@NonNull Range range, @NonNull String message) {
     this.range = range
     this.message = message

bsp4j/src/main/xtend-gen/ch/epfl/scala/bsp4j/CodeAction.java

@@ -0,0 +1,96 @@
+package ch.epfl.scala.bsp4j;
+
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.xtext.xbase.lib.Pure;
+import org.eclipse.xtext.xbase.lib.util.ToStringBuilder;
+
+@SuppressWarnings("all")
+public class CodeAction {
+  @NonNull
+  private String title;
+
+  private String description;
+
+  private WorkspaceEdit edit;
+
+  public CodeAction(@NonNull final String title) {
+    this.title = title;
+  }
+
+  @Pure
+  @NonNull
+  public String getTitle() {
+    return this.title;
+  }
+
+  public void setTitle(@NonNull final String title) {
+    this.title = Preconditions.checkNotNull(title, "title");
+  }
+
+  @Pure
+  public String getDescription() {
+    return this.description;
+  }
+
+  public void setDescription(final String description) {
+    this.description = description;
+  }
+
+  @Pure
+  public WorkspaceEdit getEdit() {
+    return this.edit;
+  }
+
+  public void setEdit(final WorkspaceEdit edit) {
+    this.edit = edit;
+  }
+
+  @Override
+  @Pure
+  public String toString() {
+    ToStringBuilder b = new ToStringBuilder(this);
+    b.add("title", this.title);
+    b.add("description", this.description);
+    b.add("edit", this.edit);
+    return b.toString();
+  }
+
+  @Override
+  @Pure
+  public boolean equals(final Object obj) {
+    if (this == obj)
+      return true;
+    if (obj == null)
+      return false;
+    if (getClass() != obj.getClass())
+      return false;
+    CodeAction other = (CodeAction) obj;
+    if (this.title == null) {
+      if (other.title != null)
+        return false;
+    } else if (!this.title.equals(other.title))
+      return false;
+    if (this.description == null) {
+      if (other.description != null)
+        return false;
+    } else if (!this.description.equals(other.description))
+      return false;
+    if (this.edit == null) {
+      if (other.edit != null)
+        return false;
+    } else if (!this.edit.equals(other.edit))
+      return false;
+    return true;
+  }
+
+  @Override
+  @Pure
+  public int hashCode() {
+    final int prime = 31;
+    int result = 1;
+    result = prime * result + ((this.title== null) ? 0 : this.title.hashCode());
+    result = prime * result + ((this.description== null) ? 0 : this.description.hashCode());
+    return prime * result + ((this.edit== null) ? 0 : this.edit.hashCode());
+  }
+}

bsp4j/src/main/xtend-gen/ch/epfl/scala/bsp4j/Diagnostic.java

@@ -29,6 +29,8 @@ public class Diagnostic {
   @JsonAdapter(JsonElementTypeAdapter.Factory.class)
   private Object data;
 
+  private List<CodeAction> actions;
+
   public Diagnostic(@NonNull final Range range, @NonNull final String message) {
     this.range = range;
     this.message = message;
@@ -108,6 +110,15 @@ public void setData(final Object data) {
     this.data = data;
   }
 
+  @Pure
+  public List<CodeAction> getActions() {
+    return this.actions;
+  }
+
+  public void setActions(final List<CodeAction> actions) {
+    this.actions = actions;
+  }
+
   @Override
   @Pure
   public String toString() {
@@ -120,6 +131,7 @@ public String toString() {
     b.add("relatedInformation", this.relatedInformation);
     b.add("dataKind", this.dataKind);
     b.add("data", this.data);
+    b.add("actions", this.actions);
     return b.toString();
   }
 
@@ -173,6 +185,11 @@ public boolean equals(final Object obj) {
         return false;
     } else if (!this.data.equals(other.data))
       return false;
+    if (this.actions == null) {
+      if (other.actions != null)
+        return false;
+    } else if (!this.actions.equals(other.actions))
+      return false;
     return true;
   }
 
@@ -188,6 +205,7 @@ public int hashCode() {
     result = prime * result + ((this.message== null) ? 0 : this.message.hashCode());
     result = prime * result + ((this.relatedInformation== null) ? 0 : this.relatedInformation.hashCode());
     result = prime * result + ((this.dataKind== null) ? 0 : this.dataKind.hashCode());
-    return prime * result + ((this.data== null) ? 0 : this.data.hashCode());
+    result = prime * result + ((this.data== null) ? 0 : this.data.hashCode());
+    return prime * result + ((this.actions== null) ? 0 : this.actions.hashCode());
   }
 }

bsp4j/src/main/xtend-gen/ch/epfl/scala/bsp4j/TextEdit.java

@@ -0,0 +1,81 @@
+package ch.epfl.scala.bsp4j;
+
+import org.eclipse.lsp4j.jsonrpc.validation.NonNull;
+import org.eclipse.lsp4j.util.Preconditions;
+import org.eclipse.xtext.xbase.lib.Pure;
+import org.eclipse.xtext.xbase.lib.util.ToStringBuilder;
+
+@SuppressWarnings("all")
+public class TextEdit {
+  @NonNull
+  private Range range;
+
+  @NonNull
+  private String newText;
+
+  public TextEdit(@NonNull final Range range, @NonNull final String newText) {
+    this.range = range;
+    this.newText = newText;
+  }
+
+  @Pure
+  @NonNull
+  public Range getRange() {
+    return this.range;
+  }
+
+  public void setRange(@NonNull final Range range) {
+    this.range = Preconditions.checkNotNull(range, "range");
+  }
+
+  @Pure
+  @NonNull
+  public String getNewText() {
+    return this.newText;
+  }
+
+  public void setNewText(@NonNull final String newText) {
+    this.newText = Preconditions.checkNotNull(newText, "newText");
+  }
+
+  @Override
+  @Pure
+  public String toString() {
+    ToStringBuilder b = new ToStringBuilder(this);
+    b.add("range", this.range);
+    b.add("newText", this.newText);
+    return b.toString();
+  }
+
+  @Override
+  @Pure
+  public boolean equals(final Object obj) {
+    if (this == obj)
+      return true;
+    if (obj == null)
+      return false;
+    if (getClass() != obj.getClass())
+      return false;
+    TextEdit other = (TextEdit) obj;
+    if (this.range == null) {
+      if (other.range != null)
+        return false;
+    } else if (!this.range.equals(other.range))
+      return false;
+    if (this.newText == null) {
+      if (other.newText != null)
+        return false;
+    } else if (!this.newText.equals(other.newText))
+      return false;
+    return true;
+  }
+
+  @Override
+  @Pure
+  public int hashCode() {
+    final int prime = 31;
+    int result = 1;
+    result = prime * result + ((this.range== null) ? 0 : this.range.hashCode());
+    return prime * result + ((this.newText== null) ? 0 : this.newText.hashCode());
+  }
+}

bsp4j/src/main/xtend-gen/ch/epfl/scala/bsp4j/WorkspaceEdit.java

@@ -0,0 +1,55 @@
+package ch.epfl.scala.bsp4j;
+
+import java.util.List;
+import org.eclipse.xtext.xbase.lib.Pure;
+import org.eclipse.xtext.xbase.lib.util.ToStringBuilder;
+
+@SuppressWarnings("all")
+public class WorkspaceEdit {
+  private List<TextEdit> changes;
+
+  public WorkspaceEdit(final List<TextEdit> changes) {
+    this.changes = changes;
+  }
+
+  @Pure
+  public List<TextEdit> getChanges() {
+    return this.changes;
+  }
+
+  public void setChanges(final List<TextEdit> changes) {
+    this.changes = changes;
+  }
+
+  @Override
+  @Pure
+  public String toString() {
+    ToStringBuilder b = new ToStringBuilder(this);
+    b.add("changes", this.changes);
+    return b.toString();
+  }
+
+  @Override
+  @Pure
+  public boolean equals(final Object obj) {
+    if (this == obj)
+      return true;
+    if (obj == null)
+      return false;
+    if (getClass() != obj.getClass())
+      return false;
+    WorkspaceEdit other = (WorkspaceEdit) obj;
+    if (this.changes == null) {
+      if (other.changes != null)
+        return false;
+    } else if (!this.changes.equals(other.changes))
+      return false;
+    return true;
+  }
+
+  @Override
+  @Pure
+  public int hashCode() {
+    return 31 * 1 + ((this.changes== null) ? 0 : this.changes.hashCode());
+  }
+}

bsp4s/src/main/scala/ch/epfl/scala/bsp/Bsp.scala

@@ -360,6 +360,36 @@ object DiagnosticRelatedInformation {
     JsonCodecMaker.makeWithRequiredCollectionFields
 }
 
+final case class CodeAction(
+    title: String,
+    description: Option[String],
+    edit: Option[WorkspaceEdit]
+)
+
+object CodeAction {
+  implicit val codec: JsonValueCodec[CodeAction] =
+    JsonCodecMaker.makeWithRequiredCollectionFields
+}
+
+final case class WorkspaceEdit(
+    changes: Option[List[TextEdit]]
+)
+
+object WorkspaceEdit {
+  implicit val codec: JsonValueCodec[WorkspaceEdit] =
+    JsonCodecMaker.makeWithRequiredCollectionFields
+}
+
+final case class TextEdit(
+    range: Range,
+    newText: String
+)
+
+object TextEdit {
+  implicit val codec: JsonValueCodec[TextEdit] =
+    JsonCodecMaker.makeWithRequiredCollectionFields
+}
+
 final case class Diagnostic(
     range: Range,
     severity: Option[DiagnosticSeverity],
@@ -368,7 +398,8 @@ final case class Diagnostic(
     message: String,
     relatedInformation: Option[List[DiagnosticRelatedInformation]],
     dataKind: Option[String],
-    data: Option[RawJson]
+    data: Option[RawJson],
+    actions: Option[List[CodeAction]]
 )
 
 object Diagnostic {