diff --git a/src/plugins/git/createGraph.js b/src/plugins/git/createGraph.js
index 36d4c46..28bbabb 100644
--- a/src/plugins/git/createGraph.js
+++ b/src/plugins/git/createGraph.js
@@ -71,9 +71,7 @@ class GraphCreator {
           target = {type: GN.COMMIT_TYPE, hash: entry.hash};
           break;
         default:
-          // eslint-disable-next-line no-unused-expressions
-          (entry.type: empty);
-          throw new Error(String(entry.type));
+          throw new Error(String((entry.type: empty)));
       }
       this.graph.addNode(GN.toRaw(target));
       this.graph.addEdge(GE.createEdge.hasContents(entryNode, target));
diff --git a/src/plugins/git/edges.js b/src/plugins/git/edges.js
index 89ac99f..9bba995 100644
--- a/src/plugins/git/edges.js
+++ b/src/plugins/git/edges.js
@@ -237,8 +237,6 @@ export function toRaw(x: StructuredAddress): RawAddress {
         ...lengthEncode(GitNode.toRaw(x.treeEntry))
       );
     default:
-      // eslint-disable-next-line no-unused-expressions
-      (x.type: empty);
-      throw new Error(x.type);
+      throw new Error((x.type: empty));
   }
 }
diff --git a/src/plugins/git/nodes.js b/src/plugins/git/nodes.js
index eed54d2..6f61a99 100644
--- a/src/plugins/git/nodes.js
+++ b/src/plugins/git/nodes.js
@@ -102,8 +102,6 @@ export function toRaw(x: StructuredAddress): RawAddress {
     case TREE_ENTRY_TYPE:
       return NodeAddress.append(_Prefix.treeEntry, x.treeHash, x.name);
     default:
-      // eslint-disable-next-line no-unused-expressions
-      (x.type: empty);
-      throw new Error(`Unexpected type ${x.type}`);
+      throw new Error(`Unexpected type ${(x.type: empty)}`);
   }
 }
diff --git a/src/plugins/github/edges.js b/src/plugins/github/edges.js
index 6495967..770f930 100644
--- a/src/plugins/github/edges.js
+++ b/src/plugins/github/edges.js
@@ -215,8 +215,6 @@ export function toRaw(x: StructuredAddress): RawAddress {
         ...lengthEncode(GithubNode.toRaw(x.referent))
       );
     default:
-      // eslint-disable-next-line no-unused-expressions
-      (x.type: empty);
-      throw new Error(x.type);
+      throw new Error((x.type: empty));
   }
 }
diff --git a/src/plugins/github/nodes.js b/src/plugins/github/nodes.js
index e59c42b..5e60818 100644
--- a/src/plugins/github/nodes.js
+++ b/src/plugins/github/nodes.js
@@ -261,15 +261,11 @@ export function toRaw(x: StructuredAddress): RawAddress {
             x.id
           );
         default:
-          // eslint-disable-next-line no-unused-expressions
-          (x.parent.type: empty);
-          throw new Error(`Bad comment parent type: ${x.parent.type}`);
+          throw new Error(`Bad comment parent type: ${(x.parent.type: empty)}`);
       }
     case USERLIKE_TYPE:
       return NodeAddress.append(_Prefix.userlike, x.login);
     default:
-      // eslint-disable-next-line no-unused-expressions
-      (x.type: empty);
-      throw new Error(`Unexpected type ${x.type}`);
+      throw new Error(`Unexpected type ${(x.type: empty)}`);
   }
 }
diff --git a/src/plugins/github/parseMarkdown.js b/src/plugins/github/parseMarkdown.js
index f0127e6..e933717 100644
--- a/src/plugins/github/parseMarkdown.js
+++ b/src/plugins/github/parseMarkdown.js
@@ -108,9 +108,7 @@ export function deformat(ast: Node): void {
       case "custom_block":
         break;
       default:
-        // eslint-disable-next-line no-unused-expressions
-        (type: empty);
-        throw new Error("unexpected type: " + type);
+        throw new Error("unexpected type: " + (type: empty));
     }
   }
 }
diff --git a/src/plugins/github/relationalView.js b/src/plugins/github/relationalView.js
index 111c9a4..54bbe3a 100644
--- a/src/plugins/github/relationalView.js
+++ b/src/plugins/github/relationalView.js
@@ -322,9 +322,9 @@ export class RelationalView {
         case N.REVIEW_TYPE:
           return reviewCommentUrlToId(json.url);
         default:
-          // eslint-disable-next-line no-unused-expressions
-          (parent.type: empty);
-          throw new Error(`Unexpected comment parent type: ${parent.type}`);
+          throw new Error(
+            `Unexpected comment parent type: ${(parent.type: empty)}`
+          );
       }
     })();
     const address: CommentAddress = {type: N.COMMENT_TYPE, id, parent};
@@ -405,9 +405,7 @@ export class RelationalView {
               this._addExtraAuthor(e, userlike);
               break;
             default:
-              // eslint-disable-next-line no-unused-expressions
-              (refType: empty);
-              throw new Error(`Unexpected refType: ${refType}`);
+              throw new Error(`Unexpected refType: ${(refType: empty)}`);
           }
         }
       }
@@ -461,10 +459,8 @@ export class RelationalView {
             entity = this.comment(address);
             break;
           default:
-            // eslint-disable-next-line no-unused-expressions
-            (address.type: empty);
             throw new Error(
-              `Unexpected referrer address type: ${address.type}`
+              `Unexpected referrer address type: ${(address.type: empty)}`
             );
         }
         if (entity == null) {
@@ -506,10 +502,8 @@ export class RelationalView {
             entity = this.userlike(address);
             break;
           default:
-            // eslint-disable-next-line no-unused-expressions
-            (address.type: empty);
             throw new Error(
-              `Unexpected referent address type: ${address.type}`
+              `Unexpected referent address type: ${(address.type: empty)}`
             );
         }
         if (entity == null) {
@@ -758,9 +752,7 @@ export class Comment extends _Entity<CommentEntry> {
         parent = this._view.review(address);
         break;
       default:
-        // eslint-disable-next-line no-unused-expressions
-        (address.type: empty);
-        throw new Error(`Unexpected parent address: ${stringify(address)}`);
+        throw new Error(`Bad parent address type: ${(address.type: empty)}`);
     }
     return assertExists(parent, address);
   }