Carve out cast logic in a helper function

src/components/stepforms/FillnaStepForm.vue

@@ -26,6 +26,7 @@ import ColumnPicker from '@/components/stepforms/ColumnPicker.vue';
 import BaseStepForm from './StepForm.vue';
 import { FillnaStep } from '@/lib/steps';
 import { DataSetColumn } from '@/lib/dataset';
+import { castFromString } from '@/lib/helpers';
 
 @StepFormComponent({
   vqbstep: 'fillna',
@@ -58,10 +59,8 @@ export default class FillnaStepForm extends BaseStepForm<FillnaStep> {
 
   submit() {
     const type = this.columnHeaders.filter(h => h.name === this.editedStep.column)[0].type;
-    if ((type === 'integer' || type === 'float') && !isNaN(Number(this.editedStep.value))) {
-      this.editedStep.value = Number(this.editedStep.value);
-    } else if (type === 'boolean') {
-      this.editedStep.value = this.editedStep.value === 'true';
+    if (type !== undefined) {
+      this.editedStep.value = castFromString(this.editedStep.value as string, type);
     }
     this.$$super.submit();
   }

src/components/stepforms/ReplaceStepForm.vue

@@ -37,6 +37,7 @@ import WidgetToReplace from '@/components/stepforms/WidgetToReplace.vue';
 import BaseStepForm from './StepForm.vue';
 import { ReplaceStep } from '@/lib/steps';
 import { DataSetColumn } from '@/lib/dataset';
+import { castFromString } from '@/lib/helpers';
 
 @StepFormComponent({
   vqbstep: 'replace',
@@ -81,19 +82,10 @@ export default class ReplaceStepForm extends BaseStepForm<ReplaceStep> {
 
   submit() {
     const type = this.columnHeaders.filter(h => h.name === this.editedStep.search_column)[0].type;
-    if (type === 'integer' || type === 'float') {
-      for (const tuple of this.editedStep.to_replace) {
-        if (!isNaN(Number(tuple[0]))) {
-          tuple[0] = Number(tuple[0]);
-        }
-        if (!isNaN(Number(tuple[1]))) {
-          tuple[1] = Number(tuple[1]);
-        }
-      }
-    } else if (type === 'boolean') {
-      for (const tuple of this.editedStep.to_replace) {
-        tuple[0] = tuple[0] === 'true';
-        tuple[1] = tuple[1] === 'true';
+    for (const tuple of this.editedStep.to_replace) {
+      if (type !== undefined) {
+        tuple[0] = castFromString(tuple[0], type);
+        tuple[1] = castFromString(tuple[1], type);
       }
     }
     this.$$super.submit();

src/lib/helpers.ts

@@ -0,0 +1,29 @@
+import { DataSetColumnType } from './dataset';
+
+function issStringBoolean(string: string): boolean {
+  return (
+    string === 'true' ||
+    string === 'false' ||
+    string === 'True' ||
+    string === 'False' ||
+    string === 'TRUE' ||
+    string === 'FALSE' ||
+    string === '1' ||
+    string === '0'
+  );
+}
+
+/**
+ * Determines if a value canto be be cast to number
+ *
+ * @param value the value to be tested
+ * @returns a boolean to determine if the value can be connverted to a number
+ */
+export function castFromString(value: string, type: DataSetColumnType) {
+  if ((type === 'integer' || type === 'float') && !isNaN(Number(value))) {
+    return Number(value);
+  } else if (type === 'boolean' && issStringBoolean(value)) {
+    return value === 'true' || value === 'True' || value === 'TRUE' || value === '1';
+  }
+  return value;
+}

tests/unit/helpers.spec.ts

@@ -0,0 +1,40 @@
+import { castFromString } from '@/lib/helpers';
+
+describe('castFromString', () => {
+  it('should cast numeric string to number type', () => {
+    const string1 = '42';
+    const string2 = '4.2';
+    expect(castFromString(string1, 'integer')).toEqual(42);
+    expect(castFromString(string2, 'float')).toEqual(4.2);
+  });
+
+  it('should not cast a string that does not convert to number type', () => {
+    const string = 'Hey';
+    expect(castFromString(string, 'integer')).toEqual('Hey');
+    expect(castFromString(string, 'float')).toEqual('Hey');
+  });
+
+  it('should cast numeric string to boolean type', () => {
+    const string1 = 'true';
+    const string2 = 'True';
+    const string3 = 'TRUE';
+    const string4 = '1';
+    const string5 = 'false';
+    const string6 = 'False';
+    const string7 = 'FALSE';
+    const string8 = '0';
+    expect(castFromString(string1, 'boolean')).toEqual(true);
+    expect(castFromString(string2, 'boolean')).toEqual(true);
+    expect(castFromString(string3, 'boolean')).toEqual(true);
+    expect(castFromString(string4, 'boolean')).toEqual(true);
+    expect(castFromString(string5, 'boolean')).toEqual(false);
+    expect(castFromString(string6, 'boolean')).toEqual(false);
+    expect(castFromString(string7, 'boolean')).toEqual(false);
+    expect(castFromString(string8, 'boolean')).toEqual(false);
+  });
+
+  it('should not cast a string that does not convert to boolean type', () => {
+    const string = 'FaLsE';
+    expect(castFromString(string, 'boolean')).toEqual('FaLsE');
+  });
+});