add option for camelCaseFn

Author: pyramation

packages/schema-typescript/src/context.ts

@@ -15,6 +15,7 @@ export interface SchemaTSOptions {
   useSingleQuotes: boolean;
   camelCase?: boolean; // defaults to false
   camelCaseFn?: (str: string) => string; // optional function to convert keys to camelCase
+  stripLeadingNonAlphabetChars?: boolean; // defaults to true, strips leading non-alphabet chars when camelCasing
   strictTypeSafety: boolean; // true uses { [k: string]: unknown; }, false uses any
   overrides?: SchemaDefinitionOverrides;
 
@@ -72,6 +73,7 @@ export const defaultSchemaTSOptions: SchemaTSOptions = {
   useSingleQuotes: true,
   camelCase: false,
   camelCaseFn: null,
+  stripLeadingNonAlphabetChars: false,
   strictTypeSafety: true,
   exclude: [],
   include: [],

packages/schema-typescript/src/schema.ts

@@ -233,7 +233,7 @@ function createPropertySignature(
   required: string[],
   schema: JSONSchema
 ): t.TSPropertySignature {
-  let camelCaseFn: (str: string) => string = toCamelCase;
+  let camelCaseFn: (str: string) => string = (str: string) => toCamelCase(str, ctx.options.stripLeadingNonAlphabetChars);
   if (ctx.options.camelCaseFn) camelCaseFn = ctx.options.camelCaseFn;
   const name = ctx.options.camelCase ? camelCaseFn(key) : key;
   const propType = getTypeForProp(ctx, prop, required, schema);