feat(spanner): add support for float32 (#2020)

This PR contains support for FLOAT32 type on Cloud Spanner.

.gitignore

@@ -12,3 +12,4 @@ system-test/*key.json
 .DS_Store
 package-lock.json
 __pycache__
+.vscode

src/codec.ts

@@ -118,6 +118,21 @@ abstract class WrappedNumber {
   abstract valueOf(): number;
 }
 
+/**
+ * @typedef Float32
+ * @see Spanner.float32
+ */
+export class Float32 extends WrappedNumber {
+  value: number;
+  constructor(value: number) {
+    super();
+    this.value = value;
+  }
+  valueOf(): number {
+    return Number(this.value);
+  }
+}
+
 /**
  * @typedef Float
  * @see Spanner.float
@@ -377,6 +392,10 @@ function decode(value: Value, type: spannerClient.spanner.v1.Type): Value {
     case 'BYTES':
       decoded = Buffer.from(decoded, 'base64');
       break;
+    case spannerClient.spanner.v1.TypeCode.FLOAT32:
+    case 'FLOAT32':
+      decoded = new Float32(decoded);
+      break;
     case spannerClient.spanner.v1.TypeCode.FLOAT64:
     case 'FLOAT64':
       decoded = new Float(decoded);
@@ -531,6 +550,7 @@ const TypeCode: {
   bool: 'BOOL',
   int64: 'INT64',
   pgOid: 'INT64',
+  float32: 'FLOAT32',
   float64: 'FLOAT64',
   numeric: 'NUMERIC',
   pgNumeric: 'NUMERIC',
@@ -567,6 +587,7 @@ interface FieldType extends Type {
 /**
  * @typedef {object} ParamType
  * @property {string} type The param type. Must be one of the following:
+ *     - float32
  *     - float64
  *     - int64
  *     - numeric
@@ -601,6 +622,10 @@ function getType(value: Value): Type {
   const isSpecialNumber =
     is.infinite(value) || (is.number(value) && isNaN(value));
 
+  if (value instanceof Float32) {
+    return {type: 'float32'};
+  }
+
   if (is.decimal(value) || isSpecialNumber || value instanceof Float) {
     return {type: 'float64'};
   }
@@ -780,6 +805,7 @@ export const codec = {
   convertProtoTimestampToDate,
   createTypeObject,
   SpannerDate,
+  Float32,
   Float,
   Int,
   Numeric,

src/index.ts

@@ -26,6 +26,7 @@ import * as streamEvents from 'stream-events';
 import * as through from 'through2';
 import {
   codec,
+  Float32,
   Float,
   Int,
   Numeric,
@@ -1671,6 +1672,22 @@ class Spanner extends GrpcService {
     return new PreciseDate(value as number);
   }
 
+  /**
+   * Helper function to get a Cloud Spanner Float32 object.
+   *
+   * @param {string|number} value The float as a number or string.
+   * @returns {Float32}
+   *
+   * @example
+   * ```
+   * const {Spanner} = require('@google-cloud/spanner');
+   * const float = Spanner.float32(10);
+   * ```
+   */
+  static float32(value): Float32 {
+    return new codec.Float32(value);
+  }
+
   /**
    * Helper function to get a Cloud Spanner Float64 object.
    *
@@ -1786,6 +1803,7 @@ class Spanner extends GrpcService {
 promisifyAll(Spanner, {
   exclude: [
     'date',
+    'float32',
     'float',
     'instance',
     'instanceConfig',
@@ -1946,4 +1964,4 @@ import * as protos from '../protos/protos';
 import IInstanceConfig = instanceAdmin.spanner.admin.instance.v1.IInstanceConfig;
 export {v1, protos};
 export default {Spanner};
-export {Float, Int, Struct, Numeric, PGNumeric, SpannerDate};
+export {Float32, Float, Int, Struct, Numeric, PGNumeric, SpannerDate};