fix: Revert untyped param type feature (#2012)

This fix is reverting the feature untyped param type added in [PR](https://togithub.com/googleapis/nodejs-spanner/pull/1869) and released in [7.4.0](https://togithub.com/googleapis/nodejs-spanner/releases/tag/v7.4.0)

This fixes issue #2009 which was introduced by untyped param type feature.

Author: surbhigarg92

samples/dml.js

@@ -288,21 +288,6 @@ function updateUsingDmlWithStruct(instanceId, databaseId, projectId) {
         params: {
           name: nameStruct,
         },
-        types: {
-          name: {
-            type: 'struct',
-            fields: [
-              {
-                name: 'FirstName',
-                type: 'string',
-              },
-              {
-                name: 'LastName',
-                type: 'string',
-              },
-            ],
-          },
-        },
       });
 
       console.log(`Successfully updated ${rowCount} record.`);

samples/struct.js

@@ -111,21 +111,6 @@ async function queryDataWithStruct(instanceId, databaseId, projectId) {
     params: {
       name: nameStruct,
     },
-    types: {
-      name: {
-        type: 'struct',
-        fields: [
-          {
-            name: 'FirstName',
-            type: 'string',
-          },
-          {
-            name: 'LastName',
-            type: 'string',
-          },
-        ],
-      },
-    },
   };
 
   // Queries rows from the Singers table
@@ -265,21 +250,6 @@ async function queryStructField(instanceId, databaseId, projectId) {
     params: {
       name: nameStruct,
     },
-    types: {
-      name: {
-        type: 'struct',
-        fields: [
-          {
-            name: 'FirstName',
-            type: 'string',
-          },
-          {
-            name: 'LastName',
-            type: 'string',
-          },
-        ],
-      },
-    },
   };
 
   // Queries rows from the Singers table

src/codec.ts

@@ -629,6 +629,10 @@ function getType(value: Value): Type {
     return {type: 'bool'};
   }
 
+  if (is.string(value)) {
+    return {type: 'string'};
+  }
+
   if (Buffer.isBuffer(value)) {
     return {type: 'bytes'};
   }
@@ -671,7 +675,6 @@ function getType(value: Value): Type {
     return {type: 'json'};
   }
 
-  // String type is also returned as unspecified to allow untyped parameters
   return {type: 'unspecified'};
 }
 

src/transaction.ts

@@ -1300,10 +1300,7 @@ export class Snapshot extends EventEmitter {
     if (!is.empty(typeMap)) {
       Object.keys(typeMap).forEach(param => {
         const type = typeMap[param];
-        const typeObject = codec.createTypeObject(type);
-        if (typeObject.code !== 'TYPE_CODE_UNSPECIFIED') {
-          paramTypes[param] = codec.createTypeObject(type);
-        }
+        paramTypes[param] = codec.createTypeObject(type);
       });
     }