feat(format-po): add foldLength and compactMultiline options

Upgrade pofile-ts to v3.1.0 and expose new serialization options:

- foldLength: Maximum line width before folding (default: 80, 0 = disable)
- compactMultiline: Compact format for multiline strings (default: true)

These options enable better compatibility with translation platforms
like Crowdin that may have issues with empty first lines in multiline
strings.

Refs: #2235

Author: swernerx

packages/cli/package.json

@@ -80,7 +80,7 @@
     "normalize-path": "^3.0.0",
     "ora": "^5.1.0",
     "picocolors": "^1.1.1",
-    "pofile-ts": "^3.0.0",
+    "pofile-ts": "^3.1.0",
     "pseudolocale": "^2.0.0",
     "source-map": "^0.7.6",
     "threads": "^1.7.0"

packages/format-po-gettext/package.json

@@ -50,7 +50,7 @@
     "cldr-core": "^45.0.0",
     "node-gettext": "^3.0.0",
     "plurals-cldr": "^2.0.1",
-    "pofile-ts": "^3.0.0"
+    "pofile-ts": "^3.1.0"
   },
   "devDependencies": {
     "@lingui/jest-mocks": "workspace:^",

packages/format-po-gettext/src/po-gettext.ts

@@ -1,6 +1,6 @@
 import { parse as parseIcu, Select, SelectCase } from "@messageformat/parser"
 import pluralsCldr from "plurals-cldr"
-import { parsePo, stringifyPo, createItem, type PoItem } from "pofile-ts"
+import { parsePo, stringifyPo, createItem, type PoItem, type SerializeOptions } from "pofile-ts"
 import gettextPlurals from "node-gettext/lib/plurals"
 
 import type { CatalogFormatter, CatalogType, MessageType } from "@lingui/conf"
@@ -514,6 +514,15 @@ export function formatter(
 
   const formatter = poFormatter(options)
 
+  // Build serialize options from the formatter options
+  const serializeOptions: SerializeOptions = {}
+  if (options.foldLength !== undefined) {
+    serializeOptions.foldLength = options.foldLength
+  }
+  if (options.compactMultiline !== undefined) {
+    serializeOptions.compactMultiline = options.compactMultiline
+  }
+
   return {
     catalogExtension: ".po",
     templateExtension: ".pot",
@@ -543,7 +552,7 @@ export function formatter(
         )
       })
 
-      return formatter.parse(stringifyPo(po), ctx) as CatalogType
+      return formatter.parse(stringifyPo(po, serializeOptions), ctx) as CatalogType
     },
 
     serialize(catalog, ctx): string {
@@ -587,7 +596,7 @@ export function formatter(
         po.items = newItems
       }
 
-      return stringifyPo(po)
+      return stringifyPo(po, serializeOptions)
     },
   }
 }

packages/format-po/package.json

@@ -46,7 +46,7 @@
     "@lingui/conf": "5.6.1",
     "@lingui/message-utils": "5.6.1",
     "date-fns": "^3.6.0",
-    "pofile-ts": "^3.0.0"
+    "pofile-ts": "^3.1.0"
   },
   "devDependencies": {
     "@lingui/jest-mocks": "workspace:^",

packages/format-po/src/__snapshots__/po.test.ts.snap

@@ -342,7 +342,14 @@ msgstr "Keeps any flags that are defined"
 
 #. js-lingui-explicit-id
 msgid "veryLongString"
-msgstr "One morning, when Gregor Samsa woke from troubled dreams, he found himself transformed in his bed into a horrible vermin. He lay on his armour-like back, and if he lifted his head a little he could see his brown belly, slightly domed and divided by arches into stiff sections. The bedding was hardly able to cover it and seemed ready to slide off any moment. His many legs, pitifully thin compared with the size of the rest of him, waved about helplessly as he looked. \\"What's happened to me?\\" he thought. It wasn't a dream. His room, a proper human"
+msgstr "One morning, when Gregor Samsa woke from troubled dreams, he found "
+"himself transformed in his bed into a horrible vermin. He lay on his "
+"armour-like back, and if he lifted his head a little he could see his "
+"brown belly, slightly domed and divided by arches into stiff sections. "
+"The bedding was hardly able to cover it and seemed ready to slide off "
+"any moment. His many legs, pitifully thin compared with the size of the "
+"rest of him, waved about helplessly as he looked. \\"What's happened to "
+"me?\\" he thought. It wasn't a dream. His room, a proper human"
 
 #. hello
 #. world

packages/format-po/src/po.ts

@@ -7,6 +7,7 @@ import {
   type PoFile,
   type PoItem,
   type Headers as POHeaders,
+  type SerializeOptions,
 } from "pofile-ts"
 
 import { CatalogFormatter, CatalogType, MessageType } from "@lingui/conf"
@@ -107,6 +108,40 @@ export type PoFormatterOptions = {
    * @default true
    */
   printPlaceholdersInComments?: boolean | { limit?: number }
+
+  /**
+   * Maximum line width before folding long strings.
+   *
+   * When a string exceeds this length, it will be split across multiple lines.
+   * Set to `0` to disable folding (strings will only break on actual newlines).
+   *
+   * @default 80
+   */
+  foldLength?: number
+
+  /**
+   * Use compact format for multiline strings.
+   *
+   * When `true` (default), multiline strings start with content on the first line:
+   * ```po
+   * msgid "First line\n"
+   * "Second line"
+   * ```
+   *
+   * When `false`, uses GNU gettext's traditional format with an empty first line:
+   * ```po
+   * msgid ""
+   * "First line\n"
+   * "Second line"
+   * ```
+   *
+   * The compact format is recommended as it's compatible with translation
+   * platforms like Crowdin that may strip empty first lines, avoiding
+   * unnecessary diffs.
+   *
+   * @default true
+   */
+  compactMultiline?: boolean
 }
 
 function isGeneratedId(id: string, message: MessageType): boolean {
@@ -288,7 +323,16 @@ export function formatter(options: PoFormatterOptions = {}): CatalogFormatter {
       }
 
       po.items = serialize(catalog, options)
-      return stringifyPo(po)
+
+      const serializeOptions: SerializeOptions = {}
+      if (options.foldLength !== undefined) {
+        serializeOptions.foldLength = options.foldLength
+      }
+      if (options.compactMultiline !== undefined) {
+        serializeOptions.compactMultiline = options.compactMultiline
+      }
+
+      return stringifyPo(po, serializeOptions)
     },
   }
 }

yarn.lock

@@ -3029,7 +3029,7 @@ __metadata:
     normalize-path: ^3.0.0
     ora: ^5.1.0
     picocolors: ^1.1.1
-    pofile-ts: ^3.0.0
+    pofile-ts: ^3.1.0
     pseudolocale: ^2.0.0
     source-map: ^0.7.6
     threads: ^1.7.0
@@ -3135,7 +3135,7 @@ __metadata:
     mockdate: ^3.0.5
     node-gettext: ^3.0.0
     plurals-cldr: ^2.0.1
-    pofile-ts: ^3.0.0
+    pofile-ts: ^3.1.0
     unbuild: 2.0.0
   languageName: unknown
   linkType: soft
@@ -3149,7 +3149,7 @@ __metadata:
     "@lingui/message-utils": 5.6.1
     date-fns: ^3.6.0
     mockdate: ^3.0.5
-    pofile-ts: ^3.0.0
+    pofile-ts: ^3.1.0
     unbuild: 2.0.0
   languageName: unknown
   linkType: soft
@@ -13769,10 +13769,10 @@ __metadata:
   languageName: node
   linkType: hard
 
-"pofile-ts@npm:^3.0.0":
-  version: 3.0.0
-  resolution: "pofile-ts@npm:3.0.0"
-  checksum: 9d4a1737a4dad8e6ae9f7716ba050a9f5c758403f57e09abff50c5613b16095d2c7e13aadfaa888ad06df3d6905153b561a23b4332d18383ee2e59d9ff664237
+"pofile-ts@npm:^3.1.0":
+  version: 3.1.0
+  resolution: "pofile-ts@npm:3.1.0"
+  checksum: 4e95606bca124b612334a80c3af7e9305da394ef74617070c0e70aa8fdf23240bd2f6882336fa90ee7f93e01cd2d758df376e682b11c5c2882a8b9ca88ffd6b5
   languageName: node
   linkType: hard