update

src/measurements/MeasurementContainer.js

@@ -4,6 +4,7 @@ const convertModule = require('../convert/index');
 
 class MeasurementContainer {
   constructor(options = {},logger) {
+    this.logger = logger || null;
     this.emitter = new EventEmitter();
     this.measurements = {};
     this.windowSize = options.windowSize || 10; // Default window size
@@ -96,7 +97,10 @@ class MeasurementContainer {
 
   variant(variantName) {
     if (!this._currentType) {
-      throw new Error('Type must be specified before variant');
+      if (this.logger) {
+        this.logger.warn('variant() ignored: type must be specified before variant');
+      }
+      return this;
     }
     this._currentVariant = variantName;
     this._currentPosition = null;
@@ -106,11 +110,13 @@ class MeasurementContainer {
 
   position(positionValue) {
     if (!this._currentVariant) {
-      throw new Error('Variant must be specified before position');
+      if (this.logger) {
+        this.logger.warn('position() ignored: variant must be specified before position');
+      }
+      return this;
     }
 
-    
-    this._currentPosition = positionValue.toString().toLowerCase();;
+    this._currentPosition = positionValue.toString().toLowerCase();
     
     return this;
   }
@@ -429,7 +435,10 @@ class MeasurementContainer {
   // Difference calculations between positions
   difference({ from = "downstream", to = "upstream", unit: requestedUnit } = {}) {
     if (!this._currentType || !this._currentVariant) {
-      throw new Error("Type and variant must be specified for difference calculation");
+      if (this.logger) {
+        this.logger.warn('difference() ignored: type and variant must be specified');
+      }
+      return null;
     }
 
     const get = pos => {
@@ -510,7 +519,10 @@ class MeasurementContainer {
 
   getVariants() {
     if (!this._currentType) {
-      throw new Error('Type must be specified before listing variants');
+      if (this.logger) {
+        this.logger.warn('getVariants() ignored: type must be specified first');
+      }
+      return [];
     }
     return this.measurements[this._currentType] ? 
       Object.keys(this.measurements[this._currentType]) : [];
@@ -518,7 +530,10 @@ class MeasurementContainer {
 
   getPositions() {
     if (!this._currentType || !this._currentVariant) {
-      throw new Error('Type and variant must be specified before listing positions');
+      if (this.logger) {
+        this.logger.warn('getPositions() ignored: type and variant must be specified first');
+      }
+      return [];
     }
     
     if (!this.measurements[this._currentType] || 
@@ -628,7 +643,10 @@ class MeasurementContainer {
     if (positionValue > 0) {
       return "downstream";
     }
-    console.log(`Invalid position provided: ${positionValue}`);
+    if (this.logger) {
+      this.logger.warn(`Invalid position provided: ${positionValue}`);
+    }
+    return null;
   }
 
 }