Fix image and sound related code to check if the referenced file exists

Merge pull request #72 from haroldo-ok/check-file-existance
This fixes #67

examples/test/src/vn_engine.c

@@ -196,7 +196,7 @@ void VN_init() {
 	XGM_setLoopNumber(-1);
 	XGM_setForceDelayDMA(TRUE);
 
-	VDP_drawText("choice4genesis v0.9.0", 18, 27);
+	VDP_drawText("choice4genesis v0.9.1", 18, 27);
 }
 
 

generator/generator.js

@@ -20,6 +20,19 @@ const getStringConstant = (entity, parameter, context, name) => {
 	return parameter[1];
 }
 
+const getFileNameConstant = (entity, parameter, context, name) => {
+	const fileName = getStringConstant(entity, parameter, context, name);
+	if (!fileName) {
+		// Assumes `getStringConstant()` already generated the error message
+		return null;
+	}
+
+	if (!context.fileSystem.fileExistsInProjectDir(fileName)) {
+		context.errors.push(buildEntityError(entity, `${name} points to a missing file: "${fileName}".`));
+	}	
+	return fileName;
+}
+
 const getNumber = (entity, parameter, context, name) => {
 	if (!parameter) {
 		context.errors.push(buildEntityError(entity, name + ' was not informed.'));
@@ -103,7 +116,7 @@ const addResource = (map, fileName, generator) => {
 const generateResource = map => Object.values(map).map(({ content }) => content).join('\n');
 
 const generateImageCommand = (functionName, entity, context, mapOption = 'ALL', generatedFlags='') => {
-	const imageFileName = getStringConstant(entity, entity.params.positional.fileName, context, 'Image filename');
+	const imageFileName = getFileNameConstant(entity, entity.params.positional.fileName, context, 'Image filename');
 	const imageVariable = addResource(context.res.gfx, imageFileName, imageVariable => 
 		`IMAGE ${imageVariable} "../project/${imageFileName}" APLIB ${mapOption}`);
 
@@ -130,15 +143,15 @@ const COMMAND_GENERATORS = {
 	'font': (entity, context) => generateImageCommand('VN_font', entity, context, 'NONE'),
 
 	'music': (entity, context) => {
-		const musicFileName = getStringConstant(entity, entity.params.positional.fileName, context, 'Music filename');
+		const musicFileName = getFileNameConstant(entity, entity.params.positional.fileName, context, 'Music filename');
 		const musicVariable = addResource(context.res.music, musicFileName, musicVariable => 
 			`XGM ${musicVariable} "../project/${musicFileName}" APLIB`);
 
 		return `VN_music(${musicVariable});`;
 	},
 
 	'sound': (entity, context) => {
-		const soundFileName = getStringConstant(entity, entity.params.positional.fileName, context, 'Sound filename');
+		const soundFileName = getFileNameConstant(entity, entity.params.positional.fileName, context, 'Sound filename');
 		const soundVariable = addResource(context.res.music, soundFileName, soundVariable => 
 			`WAV ${soundVariable} "../project/${soundFileName}" XGM`);
 
@@ -317,7 +330,7 @@ const COMMAND_GENERATORS = {
 	},
 
 	'cursor': (entity, context) => {
-		const imageFileName = getStringConstant(entity, entity.params.positional.fileName, context, 'Image filename');
+		const imageFileName = getFileNameConstant(entity, entity.params.positional.fileName, context, 'Image filename');
 		const width = getNumber(entity, entity.params.positional.width, context, 'Sprite width in tiles');
 		const height = getNumber(entity, entity.params.positional.height, context, 'Sprite height in tiles');
 		const frameDelay = getNumber(entity, entity.params.positional.frameDelay, context, 'Sprite animation delay');		

generator/transpiler.js

@@ -16,6 +16,10 @@ const transpile = commandLine => {
 			const fileName = name + '.choice';
 			const source = readFileSync(projectFolder + 'project/' + fileName, {encoding:'utf8', flag:'r'});
 			return source;
+		},
+
+		fileExistsInProjectDir: fileName => {
+			return existsSync(projectFolder + 'project/' + fileName);
 		}
 	};
 

package.json

@@ -1,6 +1,6 @@
 {
   "name": "choice4genesis",
-  "version": "0.9.0",
+  "version": "0.9.1",
   "description": "A ChoiceScript clone that generates SGDK-compatible C source for the Sega Genesis ",
   "main": "index.js",
   "scripts": {