add auto-highlighting of selected/updated code

src/application/State/Code/Event/CodeChangedEvent.ts

@@ -0,0 +1,64 @@
+import { ICodeChangedEvent } from './ICodeChangedEvent';
+import { SelectedScript } from '../../Selection/SelectedScript';
+import { IScript } from '@/domain/IScript';
+import { ICodePosition } from '@/application/State/Code/Position/ICodePosition';
+
+export class CodeChangedEvent implements ICodeChangedEvent {
+    public readonly code: string;
+    public readonly addedScripts: ReadonlyArray<IScript>;
+    public readonly removedScripts: ReadonlyArray<IScript>;
+    public readonly changedScripts: ReadonlyArray<IScript>;
+
+    private readonly scripts: Map<IScript, ICodePosition>;
+
+    constructor(
+        code: string,
+        oldScripts: ReadonlyArray<SelectedScript>,
+        scripts: Map<SelectedScript, ICodePosition>) {
+        ensureAllPositionsExist(code, Array.from(scripts.values()));
+        this.code = code;
+        const newScripts = Array.from(scripts.keys());
+        this.addedScripts = selectIfNotExists(newScripts, oldScripts);
+        this.removedScripts = selectIfNotExists(oldScripts, newScripts);
+        this.changedScripts = getChangedScripts(oldScripts, newScripts);
+        this.scripts = new Map<IScript, ICodePosition>();
+        scripts.forEach((position, selection) => {
+            this.scripts.set(selection.script, position);
+        });
+    }
+
+    public isEmpty(): boolean {
+        return this.scripts.size === 0;
+    }
+
+    public getScriptPositionInCode(script: IScript): ICodePosition {
+       return this.scripts.get(script);
+    }
+}
+
+function ensureAllPositionsExist(script: string, positions: ReadonlyArray<ICodePosition>) {
+    const totalLines = script.split(/\r\n|\r|\n/).length;
+    for (const position of positions) {
+        if (position.endLine > totalLines) {
+            throw new Error(`script end line (${position.endLine}) is out of range.` +
+                            `(total code lines: ${totalLines}`);
+        }
+    }
+}
+
+function getChangedScripts(
+    oldScripts: ReadonlyArray<SelectedScript>,
+    newScripts: ReadonlyArray<SelectedScript>): ReadonlyArray<IScript> {
+    return newScripts
+        .filter((newScript) => oldScripts.find((oldScript) => oldScript.id === newScript.id
+                               && oldScript.revert !== newScript.revert ))
+        .map((selection) => selection.script);
+}
+
+function selectIfNotExists(
+    selectableContainer: ReadonlyArray<SelectedScript>,
+    test: ReadonlyArray<SelectedScript>) {
+    return selectableContainer
+        .filter((script) => !test.find((oldScript) => oldScript.id === script.id))
+        .map((selection) => selection.script);
+}