fix(i18n): parse nested Kotlin interpolation

2026-08-27 21:07:01 -06:00 · 2026-07-12 11:15:31 +02:00
parent 569a5f44c0
commit 5b7f50c077
2 changed files with 96 additions and 9 deletions
@@ -45,7 +45,6 @@ const ARRAY_RE = /<string-array\s+name="([A-Za-z0-9_]+)"[^>]*>([\s\S]*?)<\/strin
 const ARRAY_ITEM_RE = /<item>([\s\S]*?)<\/item>/gu;
 const FORMAT_RE = /%\d+\$[a-z]/giu;
 const INVALID_APOSTROPHE_RE = /(?:&apos;|(?<!\\)')/u;
-const INTERPOLATION_RE = /\$(?:[A-Za-z_][A-Za-z0-9_]*|\{[^{}]+\})/gu;
 const GENERATED_HEADER = "    <!-- Generated by scripts/android-app-i18n.ts. -->";
 const GENERATED_KOTLIN_HEADER = "// Generated by scripts/android-app-i18n.ts. Do not edit.";

@@ -105,10 +104,75 @@ function decodeXml(value: string): string {
    .replaceAll("\\\\", "\\");
 }

+type KotlinInterpolation = {
+  end: number;
+  start: number;
+  value: string;
+};
+
+function readKotlinInterpolations(source: string): KotlinInterpolation[] | null {
+  const interpolations: KotlinInterpolation[] = [];
+  for (let index = 0; index < source.length; index += 1) {
+    if (source[index] !== "$") {
+      continue;
+    }
+    const next = source[index + 1];
+    if (next !== "{" && !/[A-Za-z_]/u.test(next ?? "")) {
+      continue;
+    }
+    const start = index;
+    if (next !== "{") {
+      index += 2;
+      while (/[A-Za-z0-9_]/u.test(source[index] ?? "")) {
+        index += 1;
+      }
+      interpolations.push({ start, end: index, value: source.slice(start, index) });
+      index -= 1;
+      continue;
+    }
+
+    let depth = 1;
+    let quote: '"' | "'" | null = null;
+    let escaped = false;
+    for (index += 2; index < source.length; index += 1) {
+      const character = source[index];
+      if (escaped) {
+        escaped = false;
+      } else if (quote !== null && character === "\\") {
+        escaped = true;
+      } else if (character === quote) {
+        quote = null;
+      } else if (quote === null && (character === '"' || character === "'")) {
+        quote = character;
+      } else if (quote === null && character === "{") {
+        depth += 1;
+      } else if (quote === null && character === "}") {
+        depth -= 1;
+        if (depth === 0) {
+          const end = index + 1;
+          interpolations.push({ start, end, value: source.slice(start, end) });
+          break;
+        }
+      }
+    }
+    if (depth !== 0) {
+      return null;
+    }
+  }
+  return interpolations;
+}
+
 export function renderAndroidResourceValue(source: string, translated: string): string {
  let rendered = translated;
-  const sourceTokens = [...source.matchAll(INTERPOLATION_RE)].map((match) => match[0]);
-  const translatedTokens = [...translated.matchAll(INTERPOLATION_RE)].map((match) => match[0]);
+  const sourceInterpolations = readKotlinInterpolations(source);
+  const translatedInterpolations = readKotlinInterpolations(translated);
+  if (sourceInterpolations === null || translatedInterpolations === null) {
+    throw new Error(
+      `Android translation has unbalanced interpolation placeholders: ${JSON.stringify(source)} -> ${JSON.stringify(translated)}`,
+    );
+  }
+  const sourceTokens = sourceInterpolations.map((interpolation) => interpolation.value);
+  const translatedTokens = translatedInterpolations.map((interpolation) => interpolation.value);
  const tokenCounts = (tokens: readonly string[]) => {
    const counts = new Map<string, number>();
    for (const token of tokens) {
@@ -122,7 +186,6 @@ export function renderAndroidResourceValue(source: string, translated: string):
    );
  }
  if (sourceTokens.length > 0) {
-    rendered = rendered.replaceAll("%", "%%");
    const sourceIndices = new Map<string, number[]>();
    for (const [index, token] of sourceTokens.entries()) {
      const indices = sourceIndices.get(token) ?? [];
@@ -130,12 +193,18 @@ export function renderAndroidResourceValue(source: string, translated: string):
      sourceIndices.set(token, indices);
    }
    const translatedOccurrences = new Map<string, number>();
-    rendered = rendered.replace(INTERPOLATION_RE, (token) => {
+    let cursor = 0;
+    rendered = "";
+    for (const interpolation of translatedInterpolations) {
+      rendered += translated.slice(cursor, interpolation.start).replaceAll("%", "%%");
+      const token = interpolation.value;
      const occurrence = translatedOccurrences.get(token) ?? 0;
      translatedOccurrences.set(token, occurrence + 1);
      const index = sourceIndices.get(token)?.[occurrence];
-      return index ? `%${index}$s` : token;
-    });
+      rendered += index ? `%${index}$s` : token;
+      cursor = interpolation.end;
+    }
+    rendered += translated.slice(cursor).replaceAll("%", "%%");
  }
  return rendered
    .replaceAll("\\", "\\\\")
@@ -837,8 +906,8 @@ function renderStringsXml(
    for (const [key, entry] of [...generated].toSorted(([left], [right]) =>
      compareText(left, right),
    )) {
-      const formatted = INTERPOLATION_RE.test(entry.source) ? "" : ' formatted="false"';
-      INTERPOLATION_RE.lastIndex = 0;
+      const formatted =
+        (readKotlinInterpolations(entry.source)?.length ?? 0) > 0 ? "" : ' formatted="false"';
      // Translation-memory text intentionally preserves technical tokens and source punctuation,
      // so Android's English dictionary and typography suggestions do not apply to managed keys.
      lines.push(
@@ -53,6 +53,24 @@ describe("Android app i18n resources", () => {
    ).toBe("%2$s Anbieter, davon %1$s bereit");
  });

+  it("formats nested Kotlin interpolations as single Android arguments", () => {
+    expect(
+      renderAndroidResourceValue(
+        "${device.tokens.count { !it.revoked }}/${device.tokens.size} active tokens",
+        "${device.tokens.size} Token, ${device.tokens.count { !it.revoked }} aktiv",
+      ),
+    ).toBe("%2$s Token, %1$s aktiv");
+  });
+
+  it("balances braces inside nested interpolation strings", () => {
+    expect(
+      renderAndroidResourceValue(
+        '${if (connected) "{" else "}"} $count',
+        '$count · ${if (connected) "{" else "}"}',
+      ),
+    ).toBe("%2$s · %1$s");
+  });
+
  it("rejects repeated translation placeholders that do not match the source", () => {
    expect(() =>
      renderAndroidResourceValue("$item then $item", "$item, $item und noch einmal $item"),