move schema sniffer to util

src/reducers/controls.js

@@ -1,48 +1,9 @@
 // jshint esversion: 6
 import _ from "lodash";
 import { parseRGB } from "../util/parseRGB";
+import { createSchemaByDataSniffing } from "../util/schema";
 var crossfilter = require("../util/typedCrossfilter");
 
-// In the case where the REST server does not implement data schema
-// declaration, we attempt to deduce it by sniffing the data.
-//
-function createSchemaByDataSniffing(ranges) {
-  let schema = {};
-  _.forEach(ranges, (value, key) => {
-    schema[key] = {
-      displayname: key,
-      variabletype: value.options ? "categorical" : "continuous"
-    };
-
-    // Metadata field type is inferred by sniffing the data. This has some risks.
-    // Caveats:
-    //  * Values have been converted to native JS objects by the JSON parser.
-    //  * Lots of assumptions about he REST API behaving properly (eg, min/max
-    //    are the same type, etc).
-    let type;
-    if (schema[key].variabletype === "continuous" && value.range) {
-      // Use min/max as a proxy for all data.
-      const min = value.range.min;
-      const max = value.range.max;
-      type =
-        typeof min !== "number" || typeof max !== "number"
-          ? "string"
-          : Number.isSafeInteger(min) && Number.isSafeInteger(max)
-            ? "int"
-            : "float";
-    } else {
-      // use an option value as a proxy for all data
-      const aVal = value.options[0];
-      type =
-        typeof aVal !== "number"
-          ? "string"
-          : Number.isSafeInteger(aVal) ? "int" : "float";
-    }
-    schema[key].type = type;
-  });
-  return schema;
-}
-
 // Deduce the correct crossfilter dimension type from a metadata
 // schema description.
 //

src/util/schema.js

@@ -0,0 +1,41 @@
+// jshint esversion: 6
+
+// In the case where the REST server does not implement data schema
+// declaration, we attempt to deduce it by sniffing the data.
+//
+export function createSchemaByDataSniffing(ranges) {
+  let schema = {};
+  _.forEach(ranges, (value, key) => {
+    schema[key] = {
+      displayname: key,
+      variabletype: value.options ? "categorical" : "continuous"
+    };
+
+    // Metadata field type is inferred by sniffing the data. This has some risks.
+    // Caveats:
+    //  * Values have been converted to native JS objects by the JSON parser.
+    //  * Lots of assumptions about he REST API behaving properly (eg, min/max
+    //    are the same type, etc).
+    let type;
+    if (schema[key].variabletype === "continuous" && value.range) {
+      // Use min/max as a proxy for all data.
+      const min = value.range.min;
+      const max = value.range.max;
+      type =
+        typeof min !== "number" || typeof max !== "number"
+          ? "string"
+          : Number.isSafeInteger(min) && Number.isSafeInteger(max)
+            ? "int"
+            : "float";
+    } else {
+      // use an option value as a proxy for all data
+      const aVal = value.options[0];
+      type =
+        typeof aVal !== "number"
+          ? "string"
+          : Number.isSafeInteger(aVal) ? "int" : "float";
+    }
+    schema[key].type = type;
+  });
+  return schema;
+}