Merge branch 'master' of github.com:browngraphicslab/Dash-Web into no_db

1 files changed, 31 insertions, 0 deletions

diff --git a/src/server/session/utilities/utilities.ts b/src/server/session/utilities/utilities.ts
new file mode 100644
index 000000000..ac8a6590a
--- /dev/null
+++ b/src/server/session/utilities/utilities.ts
@@ -0,0 +1,31 @@
+export namespace Utilities {
+
+    /**
+         * At any arbitrary layer of nesting within the configuration objects, any single value that
+         * is not specified by the configuration is given the default counterpart. If, within an object,
+         * one peer is given by configuration and two are not, the one is preserved while the two are given
+         * the default value.
+         * @returns the composition of all of the assigned objects, much like Object.assign(), but with more
+         * granularity in the overwriting of nested objects
+         */
+    export function preciseAssign(target: any, ...sources: any[]): any {
+        for (const source of sources) {
+            preciseAssignHelper(target, source);
+        }
+        return target;
+    }
+
+    export function preciseAssignHelper(target: any, source: any) {
+        Array.from(new Set([...Object.keys(target), ...Object.keys(source)])).map(property => {
+            let targetValue: any, sourceValue: any;
+            if (sourceValue = source[property]) {
+                if (typeof sourceValue === "object" && typeof (targetValue = target[property]) === "object") {
+                    preciseAssignHelper(targetValue, sourceValue);
+                } else {
+                    target[property] = sourceValue;
+                }
+            }
+        });
+    }
+
+}
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