Extracted code from mrc_class_method_def functions findLegalMethodName and isMethodNameUsed to make function makeLegalName in validator.ts.

Updated mrc_class_method_def, mrc_component, mrc_event, and mrc_mechanism blocks to use makeLegalName.

Author: lizlooney

src/blocks/mrc_class_method_def.ts

@@ -35,6 +35,7 @@ import * as toolboxItems from '../toolbox/items';
 import { getClassData } from './utils/python';
 import { FunctionData } from './utils/python_json_types';
 import { findConnectedBlocksOfType } from './utils/find_connected_blocks';
+import { makeLegalName } from './utils/validator';
 import { NONCOPYABLE_BLOCK } from './noncopyable_block';
 import { BLOCK_NAME as MRC_GET_PARAMETER_BLOCK_NAME } from './mrc_get_parameter';
 import * as paramContainer from './mrc_param_container'
@@ -285,10 +286,23 @@ const CLASS_METHOD_DEF = {
     // When the user changes the method name on the block, clear the mrcPythonMethodName field.
     this.mrcPythonMethodName = '';
 
-    // Strip leading and trailing whitespace.
-    name = name.trim();
+    if (this.isInFlyout) {
+      // Flyouts can have multiple methods with identical names.
+      return name;
+    }
+
+    const otherNames: string[] = [];
+    this.workspace.getBlocksByType(BLOCK_NAME)
+        .filter(block => block.id !== this.id)
+        .forEach((block) => {
+          otherNames.push(block.getFieldValue(FIELD_METHOD_NAME));
+          const classMethodDefBlock = block as ClassMethodDefBlock;
+          if (classMethodDefBlock.mrcPythonMethodName) {
+            otherNames.push(classMethodDefBlock.mrcPythonMethodName);
+          }
+        });
 
-    const legalName = findLegalMethodName(name, this);
+    const legalName = makeLegalName(name, otherNames, /* mustBeginWithLetter */ true);
     const oldName = nameField.getValue();
     if (oldName && oldName !== name && oldName !== legalName) {
       // Rename any callers.
@@ -366,61 +380,6 @@ const CLASS_METHOD_DEF = {
   },
 };
 
-/**
- * Ensure two identically-named methods don't exist.
- * Take the proposed method name, and return a legal name i.e. one that
- * is not empty and doesn't collide with other methods.
- *
- * @param name Proposed method name.
- * @param block Block to disambiguate.
- * @returns Non-colliding name.
- */
-function findLegalMethodName(name: string, block: ClassMethodDefBlock): string {
-  if (block.isInFlyout) {
-    // Flyouts can have multiple methods called 'my_method'.
-    return name;
-  }
-  name = name || 'unnamed';
-  while (isMethodNameUsed(name, block.workspace, block)) {
-    // Collision with another method.
-    const r = name.match(/^(.*?)(\d+)$/);
-    if (!r) {
-      name += '2';
-    } else {
-      name = r[1] + (parseInt(r[2]) + 1);
-    }
-  }
-  return name;
-}
-
-/**
- * Return if the given name is already a method name.
- *
- * @param name The questionable name.
- * @param workspace The workspace to scan for collisions.
- * @param opt_exclude Optional block to exclude from comparisons (one doesn't
- *     want to collide with oneself).
- * @returns True if the name is used, otherwise return false.
- */
-function isMethodNameUsed(
-  name: string, workspace: Blockly.Workspace, opt_exclude?: Blockly.Block): boolean {
-  const nameLowerCase = name.toLowerCase();
-  for (const block of workspace.getBlocksByType(BLOCK_NAME)) {
-    if (block === opt_exclude) {
-      continue;
-    }
-    if (nameLowerCase === block.getFieldValue(FIELD_METHOD_NAME).toLowerCase()) {
-      return true;
-    }
-    const classMethodDefBlock = block as ClassMethodDefBlock;
-    if (classMethodDefBlock.mrcPythonMethodName &&
-        nameLowerCase === classMethodDefBlock.mrcPythonMethodName.toLowerCase()) {
-      return true;
-    }
-  }
-  return false;
-}
-
 export const setup = function () {
   Blockly.Blocks[BLOCK_NAME] = CLASS_METHOD_DEF;
 };

src/blocks/mrc_component.ts

@@ -28,6 +28,7 @@ import { Editor } from '../editor/editor';
 import { ExtendedPythonGenerator } from '../editor/extended_python_generator';
 import { getModuleTypeForWorkspace } from './utils/workspaces';
 import { getAllowedTypesForSetCheck, getClassData, getSubclassNames } from './utils/python';
+import { makeLegalName } from './utils/validator';
 import * as toolboxItems from '../toolbox/items';
 import * as storageModule from '../storage/module';
 import * as storageModuleContent from '../storage/module_content';
@@ -164,10 +165,19 @@ const COMPONENT = {
     }
   },
   mrcNameFieldValidator(this: ComponentBlock, nameField: Blockly.FieldTextInput, name: string): string {
-    // Strip leading and trailing whitespace.
-    name = name.trim();
+    if (this.isInFlyout) {
+      // Flyouts can have multiple methods with identical names.
+      return name;
+    }
+
+    const otherNames: string[] = [];
+    this.workspace.getBlocksByType(BLOCK_NAME)
+        .filter(block => block.id !== this.id)
+        .forEach((block) => {
+          otherNames.push(block.getFieldValue(FIELD_NAME));
+        });
 
-    const legalName = name;
+    const legalName = makeLegalName(name, otherNames, /* mustBeginWithLetter */ true);
     const oldName = nameField.getValue();
     if (oldName && oldName !== name && oldName !== legalName) {
       // Rename any callers.

src/blocks/mrc_event.ts

@@ -23,6 +23,7 @@ import * as Blockly from 'blockly';
 
 import { MRC_STYLE_EVENTS } from '../themes/styles'
 import { createFieldNonEditableText } from '../fields/FieldNonEditableText';
+import { makeLegalName } from './utils/validator';
 import { Parameter } from './mrc_class_method_def';
 import { Editor } from '../editor/editor';
 import { ExtendedPythonGenerator } from '../editor/extended_python_generator';
@@ -185,10 +186,19 @@ const EVENT = {
     });
   },
   mrcNameFieldValidator(this: EventBlock, nameField: Blockly.FieldTextInput, name: string): string {
-    // Strip leading and trailing whitespace.
-    name = name.trim();
+    if (this.isInFlyout) {
+      // Flyouts can have multiple methods with identical names.
+      return name;
+    }
+
+    const otherNames: string[] = [];
+    this.workspace.getBlocksByType(BLOCK_NAME)
+        .filter(block => block.id !== this.id)
+        .forEach((block) => {
+          otherNames.push(block.getFieldValue(FIELD_EVENT_NAME));
+        });
 
-    const legalName = name;
+    const legalName = makeLegalName(name, otherNames, /* mustBeginWithLetter */ false);
     const oldName = nameField.getValue();
     if (oldName && oldName !== name && oldName !== legalName) {
       // Rename any callers.

src/blocks/mrc_mechanism.ts

@@ -27,6 +27,7 @@ import { createFieldNonEditableText } from '../fields/FieldNonEditableText';
 import { Editor } from '../editor/editor';
 import { ExtendedPythonGenerator } from '../editor/extended_python_generator';
 import { getAllowedTypesForSetCheck } from './utils/python';
+import { makeLegalName } from './utils/validator';
 import * as toolboxItems from '../toolbox/items';
 import * as storageModule from '../storage/module';
 import * as storageModuleContent from '../storage/module_content';
@@ -167,7 +168,19 @@ const MECHANISM = {
     // Strip leading and trailing whitespace.
     name = name.trim();
 
-    const legalName = name;
+    if (this.isInFlyout) {
+      // Flyouts can have multiple methods with identical names.
+      return name;
+    }
+
+    const otherNames: string[] = [];
+    this.workspace.getBlocksByType(BLOCK_NAME)
+        .filter(block => block.id !== this.id)
+        .forEach((block) => {
+          otherNames.push(block.getFieldValue(FIELD_NAME));
+        });
+
+    const legalName = makeLegalName(name, otherNames, /* mustBeginWithLetter */ true);
     const oldName = nameField.getValue();
     if (oldName && oldName !== name && oldName !== legalName) {
       // Rename any callers.

src/blocks/utils/validator.ts

@@ -0,0 +1,55 @@
+/**
+ * @license
+ * Copyright 2025 Google LLC
+ *
+ * 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
+ *
+ *    https://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.
+ */
+
+/**
+ * @author [email protected] (Liz Looney)
+ */
+
+/**
+ * Take the proposed name, and return a legal name.
+ * A legal name is:
+ * 1. not empty.
+ * 2. doesn't collide with other names.
+ * 3. Optional: begins with a letter.
+ */
+export function makeLegalName(proposedName: string, otherNames: string[], mustBeginWithLetter: boolean): string {
+  const otherNamesLowerCase = otherNames.map(n => n.toLowerCase());
+
+  // Strip leading and trailing whitespace.
+  let name = proposedName.trim();
+
+  // Make the name non-empty.
+  name = name || 'unnamed';
+
+  if (mustBeginWithLetter) {
+    // If the name begins with a non-alphabetic character, insert the letter a at the beginning.
+    if (!name.match(/^[a-zA-Z].*$/)) {
+      name = 'a' + name;
+    }
+  }
+
+  while (otherNamesLowerCase.includes(name.toLowerCase())) {
+    // Collision with another name.
+    const r = name.match(/^(.*?)(\d+)$/);
+    if (!r) {
+      name += '2';
+    } else {
+      name = r[1] + (parseInt(r[2]) + 1);
+    }
+  }
+  return name;
+}