mrhampson · August 9, 2018 18:33 · Aug 9, 2018 · Aug 9, 2018 · Aug 9, 2018 · Aug 9, 2018
diff --git a/defaultParamsOveruseExample.ts b/defaultParamsOveruseExample.ts
@@ -1,5 +1,5 @@
 /**
-I created this gist to point out something I consider a bad practice that I've started seeing in our typescript code:
+I created this gist to point out something I consider a bad practice that I've seen in typescript code:
 that is overuse of default parameters. The problem with overusing default parameters is that the default behavior
 of the function without args is completely implicit and requires the developer to reference the function definition and
 memorize whenever they are looking through the code.

diff --git a/defaultParamsOveruseExample.ts b/defaultParamsOveruseExample.ts
@@ -24,6 +24,7 @@ private retrieveData(activeOnly = true, inactiveOnly = false) {
 
 // Later on 
 // What is this doing? No idea without having memorize the function definition further up.
+// This boolean condition is also copy/pasted multiple times
 this.retrieveData(this.$scope.activeTabsAlerts.id === LaAlerting.ACTIVE_TAB.id);
 
 // Later on 

diff --git a/defaultParmsOveruseExample.ts → defaultParamsOveruseExample.ts b/defaultParmsOveruseExample.ts → defaultParamsOveruseExample.ts
diff --git a/defaultParmsExample.ts → defaultParmsOveruseExample.ts b/defaultParmsExample.ts → defaultParmsOveruseExample.ts
diff --git a/defaultParmsExample.ts b/defaultParmsExample.ts
@@ -1,6 +1,6 @@
 /**
 I created this gist to point out something I consider a bad practice that I've started seeing in our typescript code:
-that is overuse of default parameters. The problem with using default parameters too often is that the default behavior
+that is overuse of default parameters. The problem with overusing default parameters is that the default behavior
 of the function without args is completely implicit and requires the developer to reference the function definition and
 memorize whenever they are looking through the code.
 
@@ -9,6 +9,9 @@ was hidden behind default parameters. I refactored it by using functions that ar
 then call retrieveData with the appropriate parameters. By providing a function with a descriptive name rather than 
 letting parameter default it is much clearer what the code is doing when you are far away from the retrieveData 
 function definition.
+
+To be clear, I'm not suggesting default parameters should never be used. In certain situations they can make things 
+clearer and save repeated code. 
 */
 
 /***************************************************************

diff --git a/defaultParmsExample.ts b/defaultParmsExample.ts
@@ -4,7 +4,7 @@ that is overuse of default parameters. The problem with using default parameters
 of the function without args is completely implicit and requires the developer to reference the function definition and
 memorize whenever they are looking through the code.
 
-In the examples below I took some of our existing code that had such a function retrieveData where it's behavior 
+In the examples below I took some of our existing code that had such a function retrieveData where its behavior 
 was hidden behind default parameters. I refactored it by using functions that are named something descriptive that 
 then call retrieveData with the appropriate parameters. By providing a function with a descriptive name rather than 
 letting parameter default it is much clearer what the code is doing when you are far away from the retrieveData 
@@ -24,13 +24,13 @@ private retrieveData(activeOnly = true, inactiveOnly = false) {
 this.retrieveData(this.$scope.activeTabsAlerts.id === LaAlerting.ACTIVE_TAB.id);
 
 // Later on 
-// Same problem no idea what this means. Entirely implicit and relying on the developer memorizing the definition
+// Same problem: no idea what this means. Entirely implicit and relys on the developer memorizing the definition
 this.retrieveData(true)
 
 /***************************************************************
 * After refactor 
 ***************************************************************/
-// The functions below replace the various calls with the default parameters
+// The functions below replace the original function with default parameters
 
 // By putting the logic for which tab gets what data in this function rather than copy/pasteing a conditional statement 
 // that evaluates to the activeOnly paramter we avoid copy/paste code of the conditional and make the logic clearer

diff --git a/defaultParmsExample.ts b/defaultParmsExample.ts
@@ -0,0 +1,65 @@
+/**
+I created this gist to point out something I consider a bad practice that I've started seeing in our typescript code:
+that is overuse of default parameters. The problem with using default parameters too often is that the default behavior
+of the function without args is completely implicit and requires the developer to reference the function definition and
+memorize whenever they are looking through the code.
+
+In the examples below I took some of our existing code that had such a function retrieveData where it's behavior 
+was hidden behind default parameters. I refactored it by using functions that are named something descriptive that 
+then call retrieveData with the appropriate parameters. By providing a function with a descriptive name rather than 
+letting parameter default it is much clearer what the code is doing when you are far away from the retrieveData 
+function definition.
+*/
+
+/***************************************************************
+* Before refactor 
+***************************************************************/
+
+private retrieveData(activeOnly = true, inactiveOnly = false) {
+  // gets data
+}
+
+// Later on 
+// What is this doing? No idea without having memorize the function definition further up.
+this.retrieveData(this.$scope.activeTabsAlerts.id === LaAlerting.ACTIVE_TAB.id);
+
+// Later on 
+// Same problem no idea what this means. Entirely implicit and relying on the developer memorizing the definition
+this.retrieveData(true)
+
+/***************************************************************
+* After refactor 
+***************************************************************/
+// The functions below replace the various calls with the default parameters
+
+// By putting the logic for which tab gets what data in this function rather than copy/pasteing a conditional statement 
+// that evaluates to the activeOnly paramter we avoid copy/paste code of the conditional and make the logic clearer
+// and less prone to mistakes
+private getDataForTabId(tabId) {
+  if (tabId === LaAlerting.ACTIVE_TAB.id) {
+    this.retrieveOnlyActiveAlerts();
+  }
+  else {
+    this.retrieveAlerts();
+  }
+}
+
+private retrieveOnlyActiveAlerts() {
+  return this.retrieveData(true, false);
+}
+
+private retrieveAlerts() {
+  return this.retrieveData(false, false);
+}
+
+private retrieveData(activeOnly:boolean, inactiveOnly:boolean) {
+  // gets data
+}
+
+// Later on in code 
+// No repeated boolean logic 
+this.getDataForTabId(this.$scope.activeTabsAlerts.id);
+
+// Later on in code
+// Code is self describing and says what it does
+this.retrieveOnlyActiveAlerts();