diff --git a/src/com/google/javascript/jscomp/ijs/ConvertToTypedInterface.java b/src/com/google/javascript/jscomp/ijs/ConvertToTypedInterface.java
index bb8c8110a11..f42cceaf50c 100644
--- a/src/com/google/javascript/jscomp/ijs/ConvertToTypedInterface.java
+++ b/src/com/google/javascript/jscomp/ijs/ConvertToTypedInterface.java
@@ -310,97 +310,20 @@ static void splitNameDeclarationsAndRemoveDestructuring(Node n, NodeTraversal t)
     }
   }
 
-  private static class PropagateConstJsdoc extends NodeTraversal.AbstractPostOrderCallback {
-    final FileInfo currentFile;
+  private static class PropagateConstJsdoc extends ProcessConstJsdocCallback {
 
     PropagateConstJsdoc(FileInfo currentFile) {
-      this.currentFile = currentFile;
+      super(currentFile);
     }
 
     @Override
-    public void visit(NodeTraversal t, Node n, Node parent) {
-      switch (n.getToken()) {
-        case CLASS:
-          if (NodeUtil.isStatementParent(parent)) {
-            currentFile.recordNameDeclaration(n.getFirstChild());
-          }
-          break;
-        case FUNCTION:
-          if (NodeUtil.isStatementParent(parent)) {
-            currentFile.recordNameDeclaration(n.getFirstChild());
-          } else if (ClassUtil.isClassMethod(n) && ClassUtil.hasNamedClass(n)) {
-            currentFile.recordMethod(n);
-          }
-          break;
-        case EXPR_RESULT:
-          Node expr = n.getFirstChild();
-          switch (expr.getToken()) {
-            case CALL:
-              Node callee = expr.getFirstChild();
-              checkState(CALLS_TO_PRESERVE.contains(callee.getQualifiedName()));
-              if (callee.matchesQualifiedName("goog.provide")) {
-                currentFile.markProvided(expr.getLastChild().getString());
-              } else if (callee.matchesQualifiedName("goog.require")) {
-                currentFile.recordImport(expr.getLastChild().getString());
-              } else if (callee.matchesQualifiedName("goog.define")) {
-                currentFile.recordDefine(expr);
-              }
-              break;
-            case ASSIGN:
-              Node lhs = expr.getFirstChild();
-              propagateJsdocAtName(t, lhs);
-              currentFile.recordNameDeclaration(lhs);
-              break;
-            case GETPROP:
-              currentFile.recordNameDeclaration(expr);
-              break;
-            default:
-              throw new RuntimeException("Unexpected declaration: " + expr);
-          }
-          break;
-        case VAR:
-        case CONST:
-        case LET:
-          checkState(n.hasOneChild(), n);
-          propagateJsdocAtName(t, n.getFirstChild());
-          recordNameDeclaration(n);
-          break;
-        case STRING_KEY:
-          if (n.hasOneChild()) {
-            propagateJsdocAtName(t, n);
-          }
-          break;
-        default:
-          break;
-      }
-    }
-
-    private void recordNameDeclaration(Node decl) {
-      checkArgument(NodeUtil.isNameDeclaration(decl));
-      Node rhs = decl.getFirstChild().getLastChild();
-      boolean isImport = PotentialDeclaration.isImportRhs(rhs);
-      for (Node name : NodeUtil.findLhsNodesInNode(decl)) {
-        if (isImport) {
-          currentFile.recordImport(name.getString());
-        } else {
-          currentFile.recordNameDeclaration(name);
-        }
-      }
-    }
-
-    private void propagateJsdocAtName(NodeTraversal t, Node nameNode) {
+    protected void processConstWithRhs(NodeTraversal t, Node nameNode) {
       checkArgument(
           nameNode.isQualifiedName() || nameNode.isStringKey() || nameNode.isDestructuringLhs(),
           nameNode);
       Node jsdocNode = NodeUtil.getBestJSDocInfoNode(nameNode);
       JSDocInfo originalJsdoc = jsdocNode.getJSDocInfo();
-      if (!PotentialDeclaration.isConstToBeInferred(originalJsdoc, nameNode)) {
-        return;
-      }
       Node rhs = NodeUtil.getRValueOfLValue(nameNode);
-      if (rhs == null) {
-        return;
-      }
       JSDocInfo newJsdoc = JsdocUtil.getJSDocForRhs(rhs, originalJsdoc);
       if (newJsdoc == null && ClassUtil.isThisProp(nameNode)) {
         Var decl = findNameDeclaration(t.getScope(), rhs);
diff --git a/src/com/google/javascript/jscomp/ijs/FileInfo.java b/src/com/google/javascript/jscomp/ijs/FileInfo.java
index c2fee388ad2..61672d15c8d 100644
--- a/src/com/google/javascript/jscomp/ijs/FileInfo.java
+++ b/src/com/google/javascript/jscomp/ijs/FileInfo.java
@@ -48,7 +48,7 @@ ListMultimap<String, PotentialDeclaration> getDeclarations() {
     return declarations;
   }
 
-  private void recordDeclaration(PotentialDeclaration decl) {
+  void recordDeclaration(PotentialDeclaration decl) {
     declarations.put(decl.getFullyQualifiedName(), decl);
   }
 
diff --git a/src/com/google/javascript/jscomp/ijs/ProcessConstJsdocCallback.java b/src/com/google/javascript/jscomp/ijs/ProcessConstJsdocCallback.java
new file mode 100644
index 00000000000..9f7182df6e4
--- /dev/null
+++ b/src/com/google/javascript/jscomp/ijs/ProcessConstJsdocCallback.java
@@ -0,0 +1,127 @@
+/*
+ * Copyright 2018 The Closure Compiler Authors.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+package com.google.javascript.jscomp.ijs;
+
+import static com.google.common.base.Preconditions.checkArgument;
+import static com.google.common.base.Preconditions.checkState;
+
+import com.google.javascript.jscomp.NodeTraversal;
+import com.google.javascript.jscomp.NodeUtil;
+import com.google.javascript.rhino.JSDocInfo;
+import com.google.javascript.rhino.Node;
+
+/**
+ * A callback that calls the abstract method on every "inferrable const". This is a constant
+ * declaration for which there is no declared type and an RHS is present. This is useful for giving
+ * warnings like the CONSTANT_WITHOUT_EXPLICIT_TYPE diagnostic.
+ *
+ * As a side effect, this callback also populates the given FileInfo (assumed empty) with all of
+ * the declarations found throughout the compilation.
+ */
+abstract class ProcessConstJsdocCallback extends NodeTraversal.AbstractPostOrderCallback {
+
+  private final FileInfo currentFile;
+
+  ProcessConstJsdocCallback(FileInfo currentFile) {
+    this.currentFile = currentFile;
+  }
+
+  @Override
+  public void visit(NodeTraversal t, Node n, Node parent) {
+    switch (n.getToken()) {
+      case CLASS:
+        if (NodeUtil.isStatementParent(parent)) {
+          currentFile.recordNameDeclaration(n.getFirstChild());
+        }
+        break;
+      case FUNCTION:
+        if (NodeUtil.isStatementParent(parent)) {
+          currentFile.recordNameDeclaration(n.getFirstChild());
+        } else if (ClassUtil.isClassMethod(n) && ClassUtil.hasNamedClass(n)) {
+          currentFile.recordMethod(n);
+        }
+        break;
+      case EXPR_RESULT:
+        Node expr = n.getFirstChild();
+        switch (expr.getToken()) {
+          case CALL:
+            Node callee = expr.getFirstChild();
+            if (callee.matchesQualifiedName("goog.provide")) {
+              currentFile.markProvided(expr.getLastChild().getString());
+            } else if (callee.matchesQualifiedName("goog.require")) {
+              currentFile.recordImport(expr.getLastChild().getString());
+            } else if (callee.matchesQualifiedName("goog.define")) {
+              currentFile.recordDefine(expr);
+            }
+            break;
+          case ASSIGN:
+            Node lhs = expr.getFirstChild();
+            currentFile.recordNameDeclaration(lhs);
+            processDeclarationWithRhs(t, lhs);
+            break;
+          case GETPROP:
+            currentFile.recordNameDeclaration(expr);
+            break;
+          default:
+            throw new RuntimeException("Unexpected declaration: " + expr);
+        }
+        break;
+      case VAR:
+      case CONST:
+      case LET:
+        checkState(n.hasOneChild(), n);
+        recordNameDeclaration(n);
+        if (n.getFirstChild().isName() && n.getFirstChild().hasChildren()) {
+          processDeclarationWithRhs(t, n.getFirstChild());
+        }
+        break;
+      case STRING_KEY:
+        if (parent.isObjectLit() && n.hasOneChild()) {
+          processDeclarationWithRhs(t, n);
+        }
+        break;
+      default:
+        break;
+    }
+  }
+
+  private void recordNameDeclaration(Node decl) {
+    checkArgument(NodeUtil.isNameDeclaration(decl));
+    Node rhs = decl.getFirstChild().getLastChild();
+    boolean isImport = PotentialDeclaration.isImportRhs(rhs);
+    for (Node name : NodeUtil.findLhsNodesInNode(decl)) {
+      if (isImport) {
+        currentFile.recordImport(name.getString());
+      } else {
+        currentFile.recordNameDeclaration(name);
+      }
+    }
+  }
+
+  private void processDeclarationWithRhs(NodeTraversal t, Node lhs) {
+    checkArgument(
+        lhs.isQualifiedName() || lhs.isStringKey() || lhs.isDestructuringLhs(),
+        lhs);
+    checkState(NodeUtil.getRValueOfLValue(lhs) != null, lhs);
+    JSDocInfo originalJsdoc = NodeUtil.getBestJSDocInfo(lhs);
+    if (!PotentialDeclaration.isConstToBeInferred(originalJsdoc, lhs)) {
+      return;
+    }
+    processConstWithRhs(t, lhs);
+  }
+
+  protected abstract void processConstWithRhs(NodeTraversal t, Node lhs);
+}