diff --git a/src/analysis/GraphAnalyzer.ts b/src/analysis/GraphAnalyzer.ts
index 45e808d..8f02ce5 100644
--- a/src/analysis/GraphAnalyzer.ts
+++ b/src/analysis/GraphAnalyzer.ts
@@ -60,8 +60,13 @@ const depsShallow = (schema: OpenApiSchema): Set<Ref> => {
         return new Set(schema.anyOf.flatMap(subschema => [...depsShallow(subschema)]));
       }
       
+      if (typeof schema.type === 'undefined') {
+        return new Set(); // Any type
+      } else if (Array.isArray(schema.type)) {
+        const schemaAnyOf = { anyOf: schema.type.map(type => ({ ...schema, type })) } as OpenApiSchema;
+        return depsShallow(schemaAnyOf);
+      }
       switch (schema.type) {
-        case undefined: // Any type
         case 'null':
         case 'string':
         case 'number':
@@ -106,9 +111,13 @@ const depsDeep = (schema: OpenApiSchema, resolve: Resolve, visited: Set<Ref>): D
         return Object.assign({}, ...schema.anyOf.flatMap(subschema => depsDeep(subschema, resolve, visited)));
       }
       
+      if (typeof schema.type === 'undefined') {
+        return {}; // Any type
+      } else if (Array.isArray(schema.type)) {
+        const schemaAnyOf = { anyOf: schema.type.map(type => ({ ...schema, type })) } as OpenApiSchema;
+        return depsDeep(schemaAnyOf, resolve, visited);
+      }
       switch (schema.type) {
-        case undefined: // Any type
-          return {};
         case 'null':
         case 'string':
         case 'number':
@@ -271,9 +280,13 @@ const _isObjectSchema = (schema: OpenApiSchema, resolve: Resolve, visited: Set<R
         return false; // Union
       }
       
+      if (typeof schema.type === 'undefined') {
+        return false; // Any type
+      } else if (Array.isArray(schema.type)) {
+        const schemaAnyOf = { anyOf: schema.type.map(type => ({ ...schema, type })) } as OpenApiSchema;
+        return _isObjectSchema(schemaAnyOf, resolve, visited);
+      }
       switch (schema.type) {
-        case undefined: // Any type
-          return false; // Possibly an object, but we cannot know
         case 'null':
         case 'string':
         case 'number':
diff --git a/src/generation/effSchemGen/schemaGen.ts b/src/generation/effSchemGen/schemaGen.ts
index 4cfc2dd..ba7cf30 100644
--- a/src/generation/effSchemGen/schemaGen.ts
+++ b/src/generation/effSchemGen/schemaGen.ts
@@ -325,7 +325,7 @@ export const generateForSchema = (ctx: Context, schema: OpenApiSchema): GenResul
   } else { // Case: OpenApi.SchemaObject
     if (schema.type === 'array' || 'items' in schema) { // Case: OpenApi.ArraySchemaObject
       return generateForArraySchema(ctx, { items: {}, ...schema } as OpenApi.ArraySchemaObject);
-    } else if (isNonArraySchemaType(schema)) { // Case: OpenApi.NonArraySchemaObject
+    } else { // Case: OpenApi.NonArraySchemaObject | OpenApi.MixedSchemaObject
       if ('allOf' in schema && typeof schema.allOf !== 'undefined') {
         const schemasHead: undefined | OpenApiSchema = schema.allOf[0];
         if (schemasHead && schema.allOf.length === 1) { // If only one schema, simply generate that schema
@@ -485,7 +485,7 @@ export const generateForSchema = (ctx: Context, schema: OpenApiSchema): GenResul
                   return dedent`
                     ${commentsGenerated.commentBlock}
                     ${code}, ${commentsGenerated.commentInline}
-                  `;
+                  `.trim();
                 })
                 .join('\n')
               }
@@ -508,23 +508,29 @@ export const generateForSchema = (ctx: Context, schema: OpenApiSchema): GenResul
       if (hookResult !== null) {
         result = hookResult;
       } else {
-        switch (type) {
-          case undefined: result = generateForUnknownSchema(ctx, schema); break;
-          case 'null': result = generateForNullSchema(ctx, schema); break;
-          case 'string': result = generateForStringSchema(ctx, schema); break;
-          case 'number': result = generateForNumberSchema(ctx, schema); break;
-          case 'integer': result = generateForNumberSchema(ctx, schema); break;
-          case 'boolean': result = generateForBooleanSchema(ctx, schema); break;
-          case 'object': result = generateForObjectSchema(ctx, schema); break;
-          default: throw new TypeError(`Unsupported type "${type}"`);
+        if (typeof type === 'undefined') {
+          result = generateForUnknownSchema(ctx, schema as OpenApi.NonArraySchemaObject); // Any type
+        } else if (Array.isArray(type)) {
+          // `type` as an array is equivalent to `anyOf` with `type` set to the individual type string
+          const schemaAnyOf = { anyOf: type.map(type => ({ ...schema, type })) } as OpenApiSchema;
+          result = generateForSchema(ctx, schemaAnyOf);
+        } else {
+          const schemaNonMixed = schema as OpenApi.NonArraySchemaObject;
+          switch (type) {
+            case 'null': result = generateForNullSchema(ctx, schemaNonMixed); break;
+            case 'string': result = generateForStringSchema(ctx, schemaNonMixed); break;
+            case 'number': result = generateForNumberSchema(ctx, schemaNonMixed); break;
+            case 'integer': result = generateForNumberSchema(ctx, schemaNonMixed); break;
+            case 'boolean': result = generateForBooleanSchema(ctx, schemaNonMixed); break;
+            case 'object': result = generateForObjectSchema(ctx, schemaNonMixed); break;
+            default: throw new TypeError(`Unsupported type "${type}"`);
+          }
         }
       }
       return {
         ...result,
         code: `${result.code}`,
       };
-    } else { // Case: OpenApi.MixedSchemaObject
-      throw new Error(`Currently unsupported: MixedSchemaObject`);
     }
   }
 };
diff --git a/src/openapiToEffect.ts b/src/openapiToEffect.ts
index ecb5130..2198802 100644
--- a/src/openapiToEffect.ts
+++ b/src/openapiToEffect.ts
@@ -458,9 +458,8 @@ export const run = async (argsRaw: Array<string>): Promise<void> => {
   });
 };
 
-const [_argExec, argScript, ...args] = process.argv; // First two arguments should be the executable + script
-
 // Detect if this module is being run directly from the command line
+const [_argExec, argScript, ...args] = process.argv; // First two arguments should be the executable + script
 if (argScript && await fs.realpath(argScript) === fileURLToPath(import.meta.url)) {
   try {
     await run(args);
diff --git a/tests/fixtures/fixture0_api.json b/tests/fixtures/fixture0_api.json
index 031a07f..42c5f71 100644
--- a/tests/fixtures/fixture0_api.json
+++ b/tests/fixtures/fixture0_api.json
@@ -10,6 +10,8 @@
         "type": "object",
         "properties": {
           "name": { "type": "string" },
+          "description": { "type": ["null", "string"] },
+          "status": { "type": ["null", "string"], "enum": ["ACTIVE", "DEPRIORITIZED"] },
           "subcategories": {
             "type": "object",
             "additionalProperties": {
@@ -18,7 +20,7 @@
             "default": {}
           }
         },
-        "required": ["name"]
+        "required": ["name", "description"]
       },
       "User": {
         "type": "object",
@@ -34,7 +36,8 @@
           },
           "last_logged_in": {
             "title": "When the user last logged in.",
-            "type": "string", "format": "date-time"
+            "type": "string",
+            "format": "date-time"
           },
           "role": {
             "title": "The user's role within the system.",
diff --git a/tests/fixtures/fixture0_spec.ts b/tests/fixtures/fixture0_spec.ts
index 5d9b4ad..665d31e 100644
--- a/tests/fixtures/fixture0_spec.ts
+++ b/tests/fixtures/fixture0_spec.ts
@@ -14,10 +14,14 @@ export default {
           schemaId: 'Category',
           typeDeclarationEncoded: `{
             readonly name: string,
+            readonly description: null | string,
+            readonly status?: undefined | null | 'ACTIVE' | 'DEPRIORITIZED',
             readonly subcategories?: undefined | { readonly [key: string]: _CategoryEncoded }
           }`,
           typeDeclaration: `{
             readonly name: string,
+            readonly description: null | string,
+            readonly status?: undefined | null | 'ACTIVE' | 'DEPRIORITIZED',
             readonly subcategories: { readonly [key: string]: _Category }
           }`,
         },
diff --git a/tests/integration/fixture0.test.ts b/tests/integration/fixture0.test.ts
index 45718dd..d36d773 100644
--- a/tests/integration/fixture0.test.ts
+++ b/tests/integration/fixture0.test.ts
@@ -22,7 +22,15 @@ test('fixture0', { timeout: 30_000/*ms*/ }, async (t) => {
   const before = async () => {
     const cwd = path.dirname(fileURLToPath(import.meta.url));
     console.log('Preparing fixture0...');
-    const { stdout, stderr } = await exec(`./generate_fixture.sh fixture0`, { cwd });
+    
+    try {
+      const { stdout, stderr } = await exec(`./generate_fixture.sh fixture0`, { cwd });
+    } catch (error: unknown) {
+      if (error instanceof Error && 'stderr' in error) {
+        console.error(error.stderr);
+      }
+      throw error;
+    }
   };
   await before();
   
@@ -36,14 +44,14 @@ test('fixture0', { timeout: 30_000/*ms*/ }, async (t) => {
       last_logged_in: '2024-05-25T19:20:39.482Z',
       role: 'USER',
       interests: [
-        { name: 'Music' },
+        { name: 'Music', description: null },
       ],
     };
     assert.deepStrictEqual(S.decodeUnknownSync(fixture.User)(user1), {
       ...user1,
       last_logged_in: new Date('2024-05-25T19:20:39.482Z'), // Transformed to Date
       interests: [
-        { name: 'Music', subcategories: {} }, // Added default value
+        { name: 'Music', description: null, subcategories: {} }, // Added default value
       ],
     });
   });
diff --git a/tests/integration/fixture1.test.ts b/tests/integration/fixture1.test.ts
index 53d9d3a..1067a0e 100644
--- a/tests/integration/fixture1.test.ts
+++ b/tests/integration/fixture1.test.ts
@@ -22,7 +22,15 @@ test('fixture1', { timeout: 30_000/*ms*/ }, async (t) => {
   const before = async () => {
     const cwd = path.dirname(fileURLToPath(import.meta.url));
     console.log('Preparing fixture1...');
-    const { stdout, stderr } = await exec(`./generate_fixture.sh fixture1`, { cwd });
+    
+    try {
+      const { stdout, stderr } = await exec(`./generate_fixture.sh fixture1`, { cwd });
+    } catch (error: unknown) {
+      if (error instanceof Error && 'stderr' in error) {
+        console.error(error.stderr);
+      }
+      throw error;
+    }
   };
   await before();