feat(sassfilecontext): implement initial interface

Author: kwonoj

src/interop/context.ts

@@ -22,7 +22,7 @@ const buildContext = (
       create: () => new SassOptions(cwrapContext, cwrapOptions, mount, unmount, str) as SassOptionsInterface
     },
     file: {
-      create: () => new SassFileContext() as SassFileContextInterface
+      create: (inputPath: string) => new SassFileContext(inputPath, cwrapContext, str) as SassFileContextInterface
     }
   };
 };

src/interop/file/sassFileContext.ts

@@ -1,5 +1,83 @@
-interface SassFileContextInterface {}
+import { log } from '../../util/logger';
+import { SassOptions, SassOptionsInterface } from '../options/sassOptions';
+import { wrapSassContext } from '../wrapSassContext';
 
-class SassFileContext implements SassFileContextInterface {}
+interface SassFileContextInterface {
+  /**
+   * Property accessor to `file_context_(get|set)_options`
+   */
+  options: SassOptionsInterface | null;
+
+  /**
+   * Accessor to file_context_get_context
+   */
+  getContext(): SassContextInterface;
+
+  compile(): void;
+
+  /**
+   * Release allocated memory with created instance.
+   * Accessor to sass_delete_file_context
+   */
+  dispose(): void;
+}
+
+/**
+ * @internal
+ */
+class SassFileContext implements SassFileContextInterface {
+  private readonly sassFileContextPtr: number;
+  private sassOptions: SassOptionsInterface | null;
+
+  constructor(
+    inputPath: string,
+    private readonly cwrapCtx: ReturnType<typeof wrapSassContext>,
+    private readonly strMethod: {
+      alloc: (value: string) => number;
+      ptrToString: (value: number) => string;
+    }
+  ) {
+    const inputPathPtr = this.strMethod.alloc(inputPath);
+    this.sassFileContextPtr = this.cwrapCtx.make_file_context(inputPathPtr);
+    log(`SassFileContext: created new instance`, { sassFileContextPtr: this.sassFileContextPtr });
+  }
+
+  //Instead of reconstructing js object from raw pointer,
+  //returns reference of option instance already created.
+  public get options(): SassOptionsInterface | null {
+    const sassOptionPtr = this.cwrapCtx.file_context_get_options(this.sassFileContextPtr);
+
+    //internal access to raw pointer - interface doesn't expose it.
+    if (!!this.sassOptions && (this.sassOptions as SassOptions).sassOptionsPtr === sassOptionPtr) {
+      return this.sassOptions;
+    }
+    throw new Error(`Cannot get option`);
+  }
+
+  public set options(option: SassOptionsInterface | null) {
+    if (!option) {
+      throw new Error('Cannot set empty options');
+    }
+    this.sassOptions = null;
+    this.sassOptions = option;
+
+    //internal access to raw pointer - interface doesn't expose it.
+    this.cwrapCtx.file_context_set_options(this.sassFileContextPtr, (this.sassOptions as SassOptions).sassOptionsPtr);
+  }
+
+  public getContext(): SassContextInterface {
+    this.cwrapCtx.file_context_get_context(this.sassFileContextPtr);
+
+    throw new Error('m');
+  }
+
+  public compile(): void {
+    throw new Error('meh');
+  }
+
+  public dispose(): void {
+    this.cwrapCtx.delete_file_context(this.sassFileContextPtr);
+  }
+}
 
 export { SassFileContext, SassFileContextInterface };