Support for single-character escape sequences (#160)

Janne252 · Perryvw · commit 5afaa2da1e4c · 2018-07-28T18:15:23.000+02:00
* Support for string literal character escape sequences

* Add test files for character escape sequences

* Escape template string escape sequences
Rename to escapeString

* Complex template string escape test
diff --git a/src/Transpiler.ts b/src/Transpiler.ts
@@ -691,6 +691,30 @@ export abstract class LuaTranspiler {
         }
     }
 
+    public escapeString(text: string): string {
+        // https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String
+        const escapeSequences: Array<[RegExp, string]> = [
+            [/[\\]/g, "\\\\"],
+            [/[\']/g, "\\\'"],
+            [/[\`]/g, "\\\`"],
+            [/[\"]/g, "\\\""],
+            [/[\n]/g, "\\n"],
+            [/[\r]/g, "\\r"],
+            [/[\v]/g, "\\v"],
+            [/[\t]/g, "\\t"],
+            [/[\b]/g, "\\b"],
+            [/[\f]/g, "\\f"],
+            [/[\0]/g, "\\0"],
+        ];
+
+        if (text.length > 0) {
+            for (const [regex, replacement] of escapeSequences) {
+                text = text.replace(regex, replacement);
+            }
+        }
+        return text;
+    }
+
     public transpileExpression(node: ts.Node, brackets?: boolean): string {
         switch (node.kind) {
             case ts.SyntaxKind.BinaryExpression:
@@ -714,7 +738,7 @@ export abstract class LuaTranspiler {
                 return this.transpileIdentifier(node as ts.Identifier);
             case ts.SyntaxKind.StringLiteral:
             case ts.SyntaxKind.NoSubstitutionTemplateLiteral:
-                const text = (node as ts.StringLiteral).text;
+                const text = this.escapeString((node as ts.StringLiteral).text);
                 return `"${text}"`;
             case ts.SyntaxKind.TemplateExpression:
                 return this.transpileTemplateExpression(node as ts.TemplateExpression);
@@ -889,13 +913,15 @@ export abstract class LuaTranspiler {
     }
 
     public transpileTemplateExpression(node: ts.TemplateExpression): string {
-        const parts = [`"${node.head.text}"`];
+        const parts = [`"${this.escapeString(node.head.text)}"`];
         node.templateSpans.forEach(span => {
             const expr = this.transpileExpression(span.expression, true);
+            const text = this.escapeString(span.literal.text);
+
             if (ts.isTemplateTail(span.literal)) {
-                parts.push(`tostring(${expr}).."${span.literal.text}"`);
+                parts.push(`tostring(${expr}).."${text}"`);
             } else {
-                parts.push(`tostring(${expr}).."${span.literal.text}"`);
+                parts.push(`tostring(${expr}).."${text}"`);
             }
         });
         return parts.join("..");
diff --git a/test/translation/lua/characterEscapeSequence.lua b/test/translation/lua/characterEscapeSequence.lua
@@ -0,0 +1,18 @@
+local quoteInDoubleQuotes = "\' \' \'"
+
+local quoteInTemplateString = "\' \' \'"
+
+local doubleQuoteInQuotes = "\" \" \""
+
+local doubleQuoteInDoubleQuotes = "\" \" \""
+
+local doubleQuoteInTemplateString = "\" \" \""
+
+local escapedCharsInQuotes = "\\ \0 \b \t \n \v \f \" \' \`"
+
+local escapedCharsInDoubleQUotes = "\\ \0 \b \t \n \v \f \" \' \`"
+
+local escapedCharsInTemplateString = "\\ \0 \b \t \n \v \f \" \' \`"
+
+local nonEmptyTemplateString = "Level 0: \n\t "..tostring("Level 1: \n\t\t "..tostring("Level 3: \n\t\t\t "..tostring("Last level \n --").." \n --").." \n --").." \n --"
+
diff --git a/test/translation/ts/characterEscapeSequence.ts b/test/translation/ts/characterEscapeSequence.ts
@@ -0,0 +1,12 @@
+let quoteInDoubleQuotes = "' ' '";
+let quoteInTemplateString = `' ' '`;
+
+let doubleQuoteInQuotes = '" " "';
+let doubleQuoteInDoubleQuotes = "\" \" \"";
+let doubleQuoteInTemplateString = `" " "`;
+
+let escapedCharsInQuotes = '\\ \0 \b \t \n \v \f \" \' \`';
+let escapedCharsInDoubleQUotes = "\\ \0 \b \t \n \v \f \" \' \`";
+let escapedCharsInTemplateString = `\\ \0 \b \t \n \v \f \" \' \``;
+
+let nonEmptyTemplateString = `Level 0: \n\t ${`Level 1: \n\t\t ${`Level 3: \n\t\t\t ${'Last level \n --'} \n --`} \n --`} \n --`;
