New linter fixes

js/applesoft/compiler.ts

@@ -61,7 +61,7 @@ class LineBuffer implements IterableIterator<string> {
         return new LineBuffer(this.line, this.curChar);
     }
 
-    next(): IteratorResult<string> {
+    next(): IteratorResult<string, string | undefined> {
         if (this.atEnd()) {
             return { done: true, value: undefined };
         }
@@ -74,10 +74,10 @@ class LineBuffer implements IterableIterator<string> {
      * the token matches, the current buffer location is advanced passed
      * the token and this method returns `true`. Otherwise, this method
      * returns `false`.
-     * 
+     *
      * The input is assumed to be an all-uppercase string and the tokens
      * in the buffer are uppercased before the comparison.
-     * 
+     *
      * @param token An all-uppercase string to match.
      */
     lookingAtToken(token: string): boolean {
@@ -123,11 +123,9 @@ class LineBuffer implements IterableIterator<string> {
 export default class ApplesoftCompiler {
     private lines: Map<number, byte[]> = new Map();
 
-    constructor() { }
-
     /**
      * Loads an AppleSoft BASIC program into memory.
-     * 
+     *
      * @param mem Memory, including zero page, into which the program is
      *     loaded.
      * @param program A string with a BASIC program to compile (tokenize).
@@ -197,7 +195,7 @@ export default class ApplesoftCompiler {
                         // Backup to before the token
                         lineBuffer.backup();
                         // and emit the 'A' (upper- or lower-case)
-                        return lineBuffer.next().value.charCodeAt(0);
+                        return lineBuffer.next().value?.charCodeAt(0) ?? 0;
                     }
                 }
                 return STRING_TO_TOKEN[possibleToken];
@@ -205,7 +203,7 @@ export default class ApplesoftCompiler {
         }
 
         // If not a token, output the character upper-cased
-        return lineBuffer.next().value.toUpperCase().charCodeAt(0);
+        return lineBuffer.next().value?.toUpperCase().charCodeAt(0) ?? 0;
     }
 
     private compileLine(line: string | null | undefined) {
@@ -306,7 +304,7 @@ export default class ApplesoftCompiler {
         const lineNumbers = [...this.lines.keys()].sort();
 
         for (const lineNo of lineNumbers) {
-            const lineBytes = this.lines.get(lineNo)!;
+            const lineBytes = this.lines.get(lineNo) || [];
             const nextLineAddr = programStart + result.length + 4
                 + lineBytes.length + 1; // +1 for the zero at end of line
             result.push(nextLineAddr & 0xff, nextLineAddr >> 8);

js/applesoft/decompiler.ts

@@ -30,7 +30,7 @@ export default class ApplesoftDecompiler {
 
     /**
      * Returns a decompiler for the program in the given memory.
-     * 
+     *
      * The memory is assumed to have set `TXTTAB` and `PRGEND` correctly.
      */
     static decompilerFromMemory(ram: Memory): ApplesoftDecompiler {
@@ -50,9 +50,9 @@ export default class ApplesoftDecompiler {
      * assumed to be a dump of memory beginning at `base`. If the data
      * does not cover the whole program, attempting to decompile will
      * fail.
-     * 
+     *
      * @param program The program bytes.
-     * @param base 
+     * @param base
      */
     constructor(private readonly program: ReadonlyUint8Array,
         private readonly base: word = 0x801) {
@@ -66,8 +66,8 @@ export default class ApplesoftDecompiler {
     /**
      * Iterates through the lines of the given program in the order of
      * the linked list of lines, starting from the first line. This
-     * does _not_ mean that all lines in memory will 
+     * does _not_ mean that all lines in memory will
-     * 
+     *
      * @param from First line for which to call the callback.
      * @param to Last line for which to call the callback.
      * @param callback A function to call for each line. The first parameter
@@ -79,12 +79,12 @@ export default class ApplesoftDecompiler {
         let offset = 0;
         let nextLineAddr = this.wordAt(offset);
         let nextLineNo = this.wordAt(offset + 2);
-        while (nextLineAddr != 0 && nextLineNo < from) {
+        while (nextLineAddr !== 0 && nextLineNo < from) {
             offset = nextLineAddr;
             nextLineAddr = this.wordAt(offset);
             nextLineNo = this.wordAt(offset + 2);
         }
-        while (nextLineAddr != 0 && nextLineNo <= to) {
+        while (nextLineAddr !== 0 && nextLineNo <= to) {
             callback(offset + 2);
             offset = nextLineAddr - this.base;
             nextLineAddr = this.wordAt(offset);
@@ -105,14 +105,14 @@ export default class ApplesoftDecompiler {
         if (options.apple2 === 'e') {
             line += ' '; // D6F9: JSR SPCLIN
         }
-        line += lineNo + ' '; // D6FC, always 1 space after line number
+        line += `${lineNo} `; // D6FC, always 1 space after line number
         offset += 2;
 
         // In the original ROM, the line length is checked immediately
         // after the line number is printed. For simplicity, this method
         // always assumes that there is space for one token—which would
         // have been the case on a realy Apple.
-        while (this.program[offset] != 0) {
+        while (this.program[offset] !== 0) {
             const token = this.program[offset];
             if (token >= 0x80 && token <= 0xea) {
                 line += ' '; // D750, always put a space in front of token
@@ -158,13 +158,13 @@ export default class ApplesoftDecompiler {
     /**
      * Lists the program in the same format that an Apple II prints to the
      * screen.
-     * 
+     *
      * This method also accepts a starting and ending line number. Like on
      * an Apple II, this will print all of the lines between `from` and `to`
      * (inclusive) regardless of the actual line numbers between them.
-     * 
+     *
      * To list a single line, pass the same number for both `from` and `to`.
-     * 
+     *
      * @param options The options for formatting the output.
      * @param from The first line to print (default 0).
      * @param to The last line to print (default end of program).
@@ -193,7 +193,7 @@ export default class ApplesoftDecompiler {
         spaceIf = (nextToken: string) => /^\d/.test(nextToken);
         offset += 2;
 
-        while (this.program[offset] != 0) {
+        while (this.program[offset] !== 0) {
             const token = this.program[offset];
             let tokenString: string;
             if (token >= 0x80 && token <= 0xea) {
@@ -235,10 +235,10 @@ export default class ApplesoftDecompiler {
         let spaceIf: (char: byte) => boolean = () => false;
 
         const lineNo = this.wordAt(offset);
-        result += lineNo + ' ';
+        result += `${lineNo} `;
         offset += 2;
 
-        while (this.program[offset] != 0) {
+        while (this.program[offset] !== 0) {
             const token = this.program[offset];
             let tokenString: string;
             if (token >= 0x80 && token <= 0xea) {
@@ -290,4 +290,4 @@ export default class ApplesoftDecompiler {
         });
         return results.join('\n');
     }
-}
+}