From 4c796315e89ce580fcd3ee91420326bf0c09b8fa Mon Sep 17 00:00:00 2001
From: Philipp Fritsche <ph.fritsche@gmail.com>
Date: Tue, 26 Apr 2022 13:20:00 +0000
Subject: [PATCH] fix: improve readability of log from child process

---
 src/util/spawn.ts  | 19 ++++++++++---------
 test/util/spawn.ts |  8 ++++----
 2 files changed, 14 insertions(+), 13 deletions(-)

diff --git a/src/util/spawn.ts b/src/util/spawn.ts
index 630aea3..ec8c7ef 100644
--- a/src/util/spawn.ts
+++ b/src/util/spawn.ts
@@ -16,17 +16,18 @@ export function spawn(cmd: string, args: string[] = [], options: child_process.S
         }
         function sendBuffered (type: keyof typeof buffer, force = false) {
             const nPos = buffer[type].lastIndexOf('\n')
-            let send
-            if (force && buffer[type] && buffer[type].substr(-1) !== '\n') {
-                send = buffer[type] + '\n'
-            } else if (!force && nPos < 0) {
+            if (!force && nPos < 0 || !buffer[type]) {
                 return
-            } else {
-                send = buffer[type]
             }
-            if (send && send.trim()) {
-                (type === 'out' ? core.debug : core.warning)(send)
-                buffer[type] = buffer[type].slice(send.length)
+            const slice = force ? buffer[type] : buffer[type].slice(0, nPos + 1)
+            const lines = slice.split('\n')
+            if (lines.some(ln => ln.trim())) {
+                const logger = type === 'out' ? core.debug : core.warning
+                if (lines[lines.length -1].trim() === '') {
+                    lines.pop()
+                }
+                lines.forEach(ln => logger(ln))
+                buffer[type] = buffer[type].slice(slice.length)
             }
         }
 
diff --git a/test/util/spawn.ts b/test/util/spawn.ts
index 6fd0e41..764007a 100644
--- a/test/util/spawn.ts
+++ b/test/util/spawn.ts
@@ -51,10 +51,10 @@ test('reject on error', () => {
 
 test('defer stdout to debug', () => {
     coreDebug = []
-    spawnMock = jest.fn(() => realSpawn(process.execPath, ['-e', `process.stdout.write('foo')`]))
+    spawnMock = jest.fn(() => realSpawn(process.execPath, ['-e', `process.stdout.write('foo\\nbar')`]))
 
     return spawn('foo', ['bar', 'baz'], { uid: 123456 }).finally(() => {
-        expect(coreDebug).toEqual(['foo\n'])
+        expect(coreDebug).toEqual(['foo', 'bar'])
     })
 })
 
@@ -69,9 +69,9 @@ test('resolve to stdout', () => {
 
 test('defer stderr to warning', () => {
     coreWarning = []
-    spawnMock = jest.fn(() => realSpawn(process.execPath, ['-e', `process.stderr.write('foo')`]))
+    spawnMock = jest.fn(() => realSpawn(process.execPath, ['-e', `process.stderr.write('foo\\nbar')`]))
 
     return spawn('foo', ['bar', 'baz'], { uid: 123456 }).finally(() => {
-        expect(coreWarning).toEqual(['foo\n'])
+        expect(coreWarning).toEqual(['foo', 'bar'])
     })
 })