fix: make Actions log parser support multiple line message encoding (#38659)

fix #38652


UI part (`.log-msg`) uses "white-space: break-spaces;" so the new line
can be correctly rendered.

---------

Signed-off-by: silverwind <me@silverwind.io>
Co-authored-by: silverwind <me@silverwind.io>

web_src/js/components/ActionRunJobView.vue

@@ -722,7 +722,7 @@ async function hashChangeListener() {
 
 .job-step-logs .job-log-line .log-msg {
   flex: 1;
-  white-space: break-spaces;
+  white-space: break-spaces; /* decoded commands like "::error::foo%0Abar" contain "\n" */
   margin-left: 12px;
   overflow-wrap: anywhere;
 }

web_src/js/components/ActionRunView.test.ts

@@ -14,6 +14,13 @@ test('LogLineMessage', () => {
     '##[debug] foo': '<span class="log-msg log-cmd-debug"><span class="log-msg-label">Debug:</span><span> foo</span></span>',
     '::error::foo': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> foo</span></span>',
     '::warning file=test.js,line=1::foo': '<span class="log-msg log-cmd-warning"><span class="log-msg-label">Warning:</span><span> foo</span></span>',
+    '::error::foo%0Abar': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> foo\nbar</span></span>',
+    '::error::foo%0D%0Abar': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> foo\nbar</span></span>',
+    '::error::100%25 done%250A': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> 100% done%0A</span></span>',
+    '::error::keep%5Dsemi%3B': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> keep%5Dsemi%3B</span></span>',
+    '::group::foo%0Abar': '<span class="log-msg log-cmd-group">foo\nbar</span>',
+    '##[error]foo%0Abar%3B%5D': '<span class="log-msg log-cmd-error"><span class="log-msg-label">Error:</span><span> foo\nbar;]</span></span>',
+    '##[command]foo%0Abar': '<span class="log-msg log-cmd-command">foo%0Abar</span>',
     '::notice::foo': '<span class="log-msg log-cmd-notice"><span class="log-msg-label">Notice:</span><span> foo</span></span>',
     '::debug::foo': '<span class="log-msg log-cmd-debug"><span class="log-msg-label">Debug:</span><span> foo</span></span>',
     '##[command] foo': '<span class="log-msg log-cmd-command"> foo</span>',

web_src/js/components/ActionRunView.ts

@@ -9,7 +9,8 @@ import {POST} from '../modules/fetch.ts';
 // * Workflow command outputs log commands like "::group::the-title", "::add-matcher::...."
 // * Workflow runner parses and processes the commands to "##[group]", apply "matchers", hide secrets, etc.
 // * The reported logs are the processed logs.
-// HOWEVER: Gitea runner does not completely process those commands. Many works are done by the frontend at the moment.
+// HOWEVER: Gitea cannot, a decoded message may contain newlines and FormatLog drops them,
+// so the commands arrive here still escaped and the frontend decodes them.
 const LogLinePrefixCommandMap: Record<string, LogLineCommandName> = {
   '::group::': 'group',
   '##[group]': 'group',
@@ -67,14 +68,23 @@ const LogLineLabelMap: Partial<Record<LogLineCommandName, string>> = {
   'debug': 'Debug',
 };
 
+function decodeLineMessage(line: LogLine, cmd: LogLineCommand | null): string {
+  // TODO: for some commands (::group::), the "prefix removal" works well, for some commands with "arguments" (::remove-matcher ...::),
+  // it needs to do further processing in the future (fortunately, at the moment we don't need to handle these commands)
+  if (!cmd) return line.message;
+  let msg = line.message.substring(cmd.prefix.length);
+  if (cmd.name === 'command') return msg; // "command" is only an output tag, do not parse or escape it
+  // "##[cmd]" also escapes ";" and "]" which delimit its header, "::cmd::" does not
+  if (!cmd.prefix.startsWith('::')) msg = msg.replace(/%3B/g, ';').replace(/%5D/g, ']');
+  // renderAnsiInto breaks a line per "\r", so "%0D%0A" is one break. "%25" last keeps "%250A" literal
+  return msg.replace(/(?:%0D)?%0A/g, '\n').replace(/%0D/g, '\r').replace(/%25/g, '%');
+}
+
 export function createLogLineMessage(line: LogLine, cmd: LogLineCommand | null) {
   const logMsgAttrs = {class: 'log-msg'};
   if (cmd?.name) logMsgAttrs.class += ` log-cmd-${cmd.name}`; // make it easier to add styles to some commands like "error"
 
-  // TODO: for some commands (::group::), the "prefix removal" works well, for some commands with "arguments" (::remove-matcher ...::),
-  // it needs to do further processing in the future (fortunately, at the moment we don't need to handle these commands)
-  const msgContent = cmd ? line.message.substring(cmd.prefix.length) : line.message;
-
+  const msgContent = decodeLineMessage(line, cmd);
   const logMsg = createElementFromAttrs('span', logMsgAttrs);
   const label = cmd ? LogLineLabelMap[cmd.name] : null;
   if (label) {