8 files changed, 10 insertions, 7 deletions
diff --git a/static/panes/ast-view.js b/static/panes/ast-view.js
index de700ebbb..9ec8ff0dc 100644
--- a/static/panes/ast-view.js
+++ b/static/panes/ast-view.js
@@ -150,7 +150,7 @@ Ast.prototype.getDefaultPaneName = function () {
 };
 
 Ast.prototype.getPaneTag = function () {
-    if(this._editorid !== undefined) {
+    if(this._editorid) {
         return this._compilerName + ' (Editor #' + this._editorid + ', Compiler #' + this._compilerid + ')';
     } else {
         return this._compilerName + ' (Tree #' + this._treeid + ', Compiler #' + this._compilerid + ')';
diff --git a/static/panes/cfg-view.ts b/static/panes/cfg-view.ts
index 28baee57a..fe492c956 100644
--- a/static/panes/cfg-view.ts
+++ b/static/panes/cfg-view.ts
@@ -298,7 +298,7 @@ export class Cfg {
     }
 
     getPaneTag() {
-        if(this._editorid !== undefined) {
+        if(this._editorid) {
             return `${this._compilerName} (Editor #${this._editorid}, Compiler #${this.compilerId})`;
         } else {
             return `${this._compilerName} (Tree #${this._treeid}, Compiler #${this.compilerId})`;
diff --git a/static/panes/compiler.js b/static/panes/compiler.js
index 9e0571464..107f5a238 100644
--- a/static/panes/compiler.js
+++ b/static/panes/compiler.js
@@ -1120,7 +1120,7 @@ Compiler.prototype.handleCompileRequestAndResult = function (request, result, ca
         infoLabelText = ' - ' + timeTaken + 'ms';
     }
 
-    if (result.asmSize !== undefined) {
+    if (result.asmSize) {
         infoLabelText += ' (' + result.asmSize + 'B)';
     }
 
diff --git a/static/panes/device-view.js b/static/panes/device-view.js
index dc4fe19db..38e34f149 100644
--- a/static/panes/device-view.js
+++ b/static/panes/device-view.js
@@ -225,7 +225,7 @@ DeviceAsm.prototype.updateDeviceAsm = function () {
 };
 
 DeviceAsm.prototype.getPaneTag = function () {
-    if(this._editorId !== undefined) {
+    if(this._editorId) {
         return this._compilerName + ' (Editor #' + this._editorId + ', Compiler #' + this._compilerId + ')';
     } else {
         return this._compilerName + ' (Tree #' + this._treeId + ', Compiler #' + this._compilerId + ')';
diff --git a/static/panes/gccdump-view.js b/static/panes/gccdump-view.js
index ca2209487..b9a485a5a 100644
--- a/static/panes/gccdump-view.js
+++ b/static/panes/gccdump-view.js
@@ -330,7 +330,7 @@ GccDump.prototype.getDefaultPaneName = function () {
 };
 
 GccDump.prototype.getPaneTag = function () {
-    if(this.state._editorid !== undefined) {
+    if(this.state._editorid) {
         return this._compilerName
                 + ' (Editor #' + this.state._editorid + ', Compiler #' + this.state._compilerid + ')';
     } else {
diff --git a/static/panes/opt-view.js b/static/panes/opt-view.js
index 2339977f8..32cb6144f 100644
--- a/static/panes/opt-view.js
+++ b/static/panes/opt-view.js
@@ -138,7 +138,7 @@ Opt.prototype.getDefaultPaneName = function () {
 };
 
 Opt.prototype.getPaneTag = function () {
-    if(this._editorid !== undefined) {
+    if(this._editorid) {
         return this._compilerName + ' (Editor #' + this._editorid + ', Compiler #' + this._compilerid + ')';
     } else {
         return this._compilerName + ' (Tree #' + this._treeid + ', Compiler #' + this._compilerid + ')';
diff --git a/static/panes/pane.interfaces.ts b/static/panes/pane.interfaces.ts
index 17047df22..d8443e048 100644
--- a/static/panes/pane.interfaces.ts
+++ b/static/panes/pane.interfaces.ts
@@ -33,6 +33,9 @@ import * as monaco from 'monaco-editor';
 export class PaneState {
     id: number;
     compilerName: string;
+    // editorid and treeid are truthy numbers: if they are truthy, then they
+    // reprsent the positive integer id associated with them. If not truthy
+    // there is no editor or tree view associated with this pane.
     editorid?: number;
     treeid?: number;
 }
diff --git a/static/panes/pane.ts b/static/panes/pane.ts
index 28beead0d..0f4f9f0b0 100644
--- a/static/panes/pane.ts
+++ b/static/panes/pane.ts
@@ -200,7 +200,7 @@ export abstract class Pane<S> {
     /** Generate "(Editor #1, Compiler #1)" tag */
     protected getPaneTag() {
         const { compilerName, editorId, treeId, compilerId } = this.compilerInfo;
-        if(editorId !== undefined) {
+        if(editorId) {
             return `${compilerName} (Editor #${editorId}, Compiler #${compilerId})`;
         } else {
             return `${compilerName} (Tree #${treeId}, Compiler #${compilerId})`;