fixup! chore: add guard-for-in eslint rule

packages/td-tools/src/td-parser.ts

@@ -29,6 +29,32 @@ const logWarn = debug(`${namespace}:warn`);
 
 type AffordanceElement = PropertyElement | ActionElement | EventElement;
 
+/**
+ * Initializes the affordances field of a thing with an empty object if its
+ * type should be incorrect or undefined.
+ *
+ * This avoids potential errors that could occur due to an undefined
+ * affordance field.
+ *
+ * @param thing The Thing whose affordance field is being adjusted.
+ * @param affordanceKey The key of the affordance field.
+ */
+function adjustAffordanceField(thing: Thing, affordanceKey: string) {
+    const affordance = thing[affordanceKey];
+
+    if (typeof affordance !== "object" || affordance == null) {
+        thing[affordanceKey] = {};
+    }
+}
+
+function adjustBooleanField(affordance: AffordanceElement, key: string) {
+    const currentValue = affordance[key];
+
+    if (currentValue === undefined || typeof currentValue !== "boolean") {
+        affordance[key] = false;
+    }
+}
+
 /** Parses a TD into a Thing object */
 export function parseTD(td: string, normalize?: boolean): Thing {
     logDebug(`parseTD() parsing\n\`\`\`\n${td}\n\`\`\``);
@@ -100,14 +126,6 @@ export function parseTD(td: string, normalize?: boolean): Thing {
         thing["@type"] = [TD.DEFAULT_THING_TYPE, semType];
     }
 
-    const adjustBooleanField = (affordance: AffordanceElement, key: string) => {
-        const currentValue = affordance[key];
-
-        if (currentValue === undefined || typeof currentValue !== "boolean") {
-            affordance[key] = false;
-        }
-    };
-
     for (const property of Object.values(thing.properties ?? {})) {
         for (const key of ["readOnly", "writeOnly", "observable"]) {
             adjustBooleanField(property, key);
@@ -120,10 +138,9 @@ export function parseTD(td: string, normalize?: boolean): Thing {
         }
     }
 
-    // avoid errors due to 'undefined'
-    thing.properties ??= {};
-    thing.actions ??= {};
-    thing.events ??= {};
+    for (const affordanceKey of ["properties", "actions", "events"]) {
+        adjustAffordanceField(thing, affordanceKey);
+    }
 
     if (thing.security === undefined) {
         logWarn("parseTD() found no security metadata");
@@ -136,7 +153,7 @@ export function parseTD(td: string, normalize?: boolean): Thing {
     // collect all forms for normalization and use iterations also for checking
     const allForms = [];
     // properties
-    for (const [propName, prop] of Object.entries(thing.properties)) {
+    for (const [propName, prop] of Object.entries(thing.properties ?? {})) {
         // ensure forms mandatory forms field
         if (prop.forms == null) {
             throw new Error(`Property '${propName}' has no forms field`);
@@ -153,7 +170,7 @@ export function parseTD(td: string, normalize?: boolean): Thing {
         }
     }
     // actions
-    for (const [actName, act] of Object.entries(thing.actions)) {
+    for (const [actName, act] of Object.entries(thing.actions ?? {})) {
         // ensure forms mandatory forms field
         if (act.forms == null) {
             throw new Error(`Action '${actName}' has no forms field`);
@@ -170,7 +187,7 @@ export function parseTD(td: string, normalize?: boolean): Thing {
         }
     }
     // events
-    for (const [evtName, evt] of Object.entries(thing.events)) {
+    for (const [evtName, evt] of Object.entries(thing.events ?? {})) {
         // ensure forms mandatory forms field
         if (evt.forms == null) {
             throw new Error(`Event '${evtName}' has no forms field`);