TASK-006: Enhance documentation and tests for strict undefined handling in config management (#41)

config-manager.js

@@ -190,11 +190,17 @@ function generateConfigHash(config) {
  * Compute effective item states respecting explicit overrides over collections
  * 
  * This function builds membership maps per section and returns effectively enabled items with reasons.
- * It uses the following precedence rules:
- * 1. Explicit true/false overrides everything (highest priority)
+ * It uses strict comparisons to ensure undefined values are never treated as explicitly disabled.
+ * 
+ * Precedence rules with strict undefined handling:
+ * 1. Explicit true/false overrides everything (highest priority) - uses strict === comparisons
  * 2. If undefined and enabled by collection, use true
  * 3. Otherwise, use false (disabled)
  * 
+ * CRITICAL: Only values that are strictly === false are treated as explicitly disabled.
+ * undefined, null, 0, '', or other falsy values are NOT treated as explicit disabling.
+ * This allows collections to enable items that are not explicitly configured.
+ * 
  * @param {Object} config - Configuration object with sections
  * @returns {Object} Effective states for each section with { itemName: { enabled: boolean, reason: string } }
  *                   Reason can be: 'explicit', 'collection', or 'disabled'
@@ -253,10 +259,13 @@ function computeEffectiveItemStates(config) {
       const explicitValue = sectionConfig[itemName];
       const isEnabledByCollection = collectionEnabled.has(itemName);
 
-      // Precedence rules:
-      // 1. If explicitly set to true or false, use that value
+      // Precedence rules with strict undefined handling:
+      // 1. If explicitly set to true or false, use that value (highest priority)
       // 2. If undefined and enabled by collection, use true
-      // 3. Otherwise, use false
+      // 3. Otherwise, use false (disabled)
+      //
+      // IMPORTANT: Only strict === false comparisons are used to determine explicit disabling.
+      // undefined values are NEVER treated as explicitly disabled, allowing collections to enable them.
 
       let enabled = false;
       let reason = "disabled";
@@ -265,9 +274,11 @@ function computeEffectiveItemStates(config) {
         enabled = true;
         reason = "explicit";
       } else if (explicitValue === false) {
+        // Strict comparison ensures only explicit false disables items
         enabled = false;
         reason = "explicit";
       } else if (explicitValue === undefined && isEnabledByCollection) {
+        // undefined values can be enabled by collections (not treated as disabled)
         enabled = true;
         reason = "collection";
       }

test-effective-states.js

@@ -164,7 +164,50 @@ function runTests() {
            'Chat mode should be enabled by collection');
   });
 
-  // Test 8: getEffectivelyEnabledItems returns Sets format
+  // Test 9: TASK-006 - Strict false checks prevent undefined treated as disabled
+  test("TASK-006: Strict false checks prevent undefined treated as disabled", () => {
+    const config = {
+      prompts: {
+        'explicit-false-item': false,
+        'explicit-true-item': true,
+        // 'undefined-item' is undefined (not set)
+      },
+      collections: {
+        'testing-automation': true
+      }
+    };
+    const result = computeEffectiveItemStates(config);
+    
+    // Explicit false should be disabled with reason 'explicit'
+    const explicitFalse = result.prompts['explicit-false-item'];
+    if (explicitFalse) {
+      assert(explicitFalse.reason === 'explicit' && !explicitFalse.enabled,
+             'Items with explicit false should be disabled with reason explicit');
+    }
+    
+    // Explicit true should be enabled with reason 'explicit'  
+    const explicitTrue = result.prompts['explicit-true-item'];
+    if (explicitTrue) {
+      assert(explicitTrue.reason === 'explicit' && explicitTrue.enabled,
+             'Items with explicit true should be enabled with reason explicit');
+    }
+    
+    // Undefined item in collection should be enabled with reason 'collection'
+    const undefinedInCollection = result.prompts['playwright-generate-test'];
+    if (undefinedInCollection) {
+      assert(undefinedInCollection.reason === 'collection' && undefinedInCollection.enabled,
+             'Undefined items should be enabled by collections, not treated as explicitly disabled');
+    }
+    
+    // Undefined item NOT in collection should be disabled with reason 'disabled' (not 'explicit')
+    const undefinedNotInCollection = result.prompts['some-random-item-not-in-any-collection'];
+    if (undefinedNotInCollection) {
+      assert(undefinedNotInCollection.reason === 'disabled' && !undefinedNotInCollection.enabled,
+             'Undefined items not in collections should have reason disabled, not explicit');
+    }
+  });
+
+  // Test 10: getEffectivelyEnabledItems returns Sets format
   test("getEffectivelyEnabledItems returns Sets format", () => {
     const config = {
       prompts: {