From 39feab1ccfb8884d21d015cf83a219ee8b7398fb Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Sun, 23 Jul 2023 21:16:30 +0200
Subject: [PATCH 1/8] Add working happy path for if / end block conditions

---
 lib/utils.js                  | 61 ++++++++++++++++++++++++++++-------
 test/lib/utils.public.test.js |  5 +++
 2 files changed, 54 insertions(+), 12 deletions(-)

diff --git a/lib/utils.js b/lib/utils.js
index db3536ba..9b79d5df 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -263,16 +263,53 @@ function prettifyLevel ({ log, colorizer = defaultColorizer, levelKey = LEVEL_KE
  */
 function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colorizer = defaultColorizer, levelLabel = LEVEL_LABEL, levelKey = LEVEL_KEY, customLevels, useOnlyCustomProps }) {
   if (messageFormat && typeof messageFormat === 'string') {
-    const message = String(messageFormat).replace(/{([^{}]+)}/g, function (match, p1) {
-      // return log level as string instead of int
-      let level
-      if (p1 === levelLabel && (level = getPropertyValue(log, levelKey)) !== undefined) {
-        const condition = useOnlyCustomProps ? customLevels === undefined : customLevels[level] === undefined
-        return condition ? LEVELS[level] : customLevels[level]
-      }
-      // Parse nested key access, e.g. `{keyA.subKeyB}`.
-      return getPropertyValue(log, p1) || ''
-    })
+    // console.log(
+    //   "pino-pretty | prettifyMessage | messageFormat: ",
+    //   messageFormat
+    // );
+    // console.log(
+    //   "pino-pretty | prettifyMessage | typeof messageFormat: ",
+    //   typeof messageFormat
+    // );
+    // console.log("pino-pretty | prettifyMessage | log: ", log);
+    // console.log("pino-pretty | prettifyMessage | typeof log: ", typeof log);
+
+    const parseMessageFormat = (input, log) => {
+      input = input.replace(/{if (.*?)}(.*?){end}/g, function (_, key, value) {
+        // console.log(`_: "${_}"`);
+        // console.log(`key: "${key}"`);
+        // console.log(`value: "${value}"`);
+        const propertyValue = getPropertyValue(log, key)
+        if (propertyValue) {
+          return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
+        } else {
+          return ''
+        }
+      })
+
+      // console.log(`input: "${input}"`);
+      const replacedInput = input.replace(/\s+/g, ' ').trim()
+      // console.log(`replacedInput: "${replacedInput}"`);
+      return replacedInput
+    }
+
+    const parsedMessageFormat = parseMessageFormat(messageFormat, log)
+    // console.log("parsedMessageFormat", parsedMessageFormat);
+
+    const message = String(parsedMessageFormat).replace(
+      /{([^{}]+)}/g,
+      function (match, p1) {
+        // return log level as string instead of int
+        let level
+        if (p1 === levelLabel && (level = getPropertyValue(log, levelKey)) !== undefined) {
+          const condition = useOnlyCustomProps ? customLevels === undefined : customLevels[level] === undefined
+          return condition ? LEVELS[level] : customLevels[level]
+        }
+        // console.log('pino-pretty | prettifyMessage | p1: ', p1)
+
+        // Parse nested key access, e.g. `{keyA.subKeyB}`.
+        return getPropertyValue(log, p1) || ''
+      })
     return colorizer.message(message)
   }
   if (messageFormat && typeof messageFormat === 'function') {
@@ -383,7 +420,7 @@ function prettifyObject ({
   // Split object keys into two categories: error and non-error
   const { plain, errors } = Object.entries(input).reduce(({ plain, errors }, [k, v]) => {
     if (keysToIgnore.includes(k) === false) {
-      // Pre-apply custom prettifiers, because all 3 cases below will need this
+    // Pre-apply custom prettifiers, because all 3 cases below will need this
       const pretty = typeof customPrettifiers[k] === 'function'
         ? customPrettifiers[k](v, k, input)
         : v
@@ -557,7 +594,7 @@ function splitPropertyKey (key) {
  *
  * @param {object} obj The object to be searched.
  * @param {string|string[]} property A string, or an array of strings, identifying
-  * the property to be retrieved from the object.
+ * the property to be retrieved from the object.
  * Accepts nested properties delimited by a `.`.
  * Delimiter can be escaped to preserve property names that contain the delimiter.
  * e.g. `'prop1.prop2'` or `'prop2\.domain\.corp.prop2'`.
diff --git a/test/lib/utils.public.test.js b/test/lib/utils.public.test.js
index c6b20e2c..068af254 100644
--- a/test/lib/utils.public.test.js
+++ b/test/lib/utils.public.test.js
@@ -141,6 +141,11 @@ tap.test('prettifyMessage', t => {
     t.equal(str, 'localhost/test - param:  - foo')
   })
 
+  t.test('`messageFormat` supports conditional blocks', async t => {
+    const str = prettifyMessage({ log: { level: 30, req: { id: 'foo' } }, messageFormat: '{level} | {if req.id}({req.id}){end}{if msg}{msg}{end}' })
+    t.equal(str, '30 | (foo)')
+  })
+
   t.test('`messageFormat` supports function definition', async t => {
     const str = prettifyMessage({
       log: { level: 30, request: { url: 'localhost/test' }, msg: 'incoming request' },

From 2acc0fe646afe2111a9eecd89e33dd642272862e Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Sun, 23 Jul 2023 22:14:48 +0200
Subject: [PATCH 2/8] Refactor parsing of messageFormat conditionals in a
 separate function

---
 lib/utils.js                     | 64 ++++++++++++++++----------------
 test/lib/utils.internals.test.js | 26 +++++++++++++
 2 files changed, 57 insertions(+), 33 deletions(-)

diff --git a/lib/utils.js b/lib/utils.js
index 9b79d5df..9ad71c13 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -42,7 +42,8 @@ module.exports.internals = {
   deleteLogProperty,
   splitPropertyKey,
   createDate,
-  isValidDate
+  isValidDate,
+  parseMessageFormat
 }
 
 /**
@@ -263,38 +264,7 @@ function prettifyLevel ({ log, colorizer = defaultColorizer, levelKey = LEVEL_KE
  */
 function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colorizer = defaultColorizer, levelLabel = LEVEL_LABEL, levelKey = LEVEL_KEY, customLevels, useOnlyCustomProps }) {
   if (messageFormat && typeof messageFormat === 'string') {
-    // console.log(
-    //   "pino-pretty | prettifyMessage | messageFormat: ",
-    //   messageFormat
-    // );
-    // console.log(
-    //   "pino-pretty | prettifyMessage | typeof messageFormat: ",
-    //   typeof messageFormat
-    // );
-    // console.log("pino-pretty | prettifyMessage | log: ", log);
-    // console.log("pino-pretty | prettifyMessage | typeof log: ", typeof log);
-
-    const parseMessageFormat = (input, log) => {
-      input = input.replace(/{if (.*?)}(.*?){end}/g, function (_, key, value) {
-        // console.log(`_: "${_}"`);
-        // console.log(`key: "${key}"`);
-        // console.log(`value: "${value}"`);
-        const propertyValue = getPropertyValue(log, key)
-        if (propertyValue) {
-          return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
-        } else {
-          return ''
-        }
-      })
-
-      // console.log(`input: "${input}"`);
-      const replacedInput = input.replace(/\s+/g, ' ').trim()
-      // console.log(`replacedInput: "${replacedInput}"`);
-      return replacedInput
-    }
-
     const parsedMessageFormat = parseMessageFormat(messageFormat, log)
-    // console.log("parsedMessageFormat", parsedMessageFormat);
 
     const message = String(parsedMessageFormat).replace(
       /{([^{}]+)}/g,
@@ -305,7 +275,6 @@ function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colori
           const condition = useOnlyCustomProps ? customLevels === undefined : customLevels[level] === undefined
           return condition ? LEVELS[level] : customLevels[level]
         }
-        // console.log('pino-pretty | prettifyMessage | p1: ', p1)
 
         // Parse nested key access, e.g. `{keyA.subKeyB}`.
         return getPropertyValue(log, p1) || ''
@@ -803,3 +772,32 @@ function handleCustomlevelNamesOpts (cLevels) {
     return {}
   }
 }
+
+/**
+ * Translates all conditional blocks from within the messageFormat. Translates any matching
+ * {if key}{key}{end} statements and returns everything between if and else blocks if the key provided
+ * was found in log.
+ *
+ * @param {string} messageFormat A format string or function that defines how the
+ *  logged message should be conditionally formatted, e.g. `'{if level}{level}{end} - {if req.id}{req.id}{end}'`.
+ * @param {object} log The log object to be modified.
+ *
+ * @returns {string} The parsed messageFormat.
+ */
+function parseMessageFormat (messageFormat, log) {
+  messageFormat = messageFormat.replace(/{if (.*?)}(.*?){end}/g, function (_, key, value) {
+    const propertyValue = getPropertyValue(log, key)
+    if (propertyValue) {
+      return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
+    } else {
+      return ''
+    }
+  })
+
+  // Remove unescaped if blocks
+  messageFormat = messageFormat.replace(/{if (.*?)}/g, '')
+  // Remove unescaped end blocks
+  messageFormat = messageFormat.replace(/{end}/g, '')
+
+  return messageFormat.replace(/\s+/g, ' ').trim()
+}
diff --git a/test/lib/utils.internals.test.js b/test/lib/utils.internals.test.js
index a0c2ea91..4dbb70cb 100644
--- a/test/lib/utils.internals.test.js
+++ b/test/lib/utils.internals.test.js
@@ -222,3 +222,29 @@ tap.test('#getPropertyValue', t => {
 
   t.end()
 })
+
+tap.test('#parseMessageFormat', t => {
+  const logData = {
+    level: 30,
+    data1: {
+      data2: 'bar'
+    }
+  }
+
+  t.test('parseMessageFormat translates if / else statement to found property value', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}{end}', log), '{level} - bar')
+  })
+
+  t.test('parseMessageFormat removes unescaped if statements', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}', log), '{level} - {data1.data2}')
+  })
+
+  t.test('parseMessageFormat removes unescaped end statements', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level} - {data1.data2}{end}', log), '{level} - {data1.data2}')
+  })
+
+  t.end()
+})

From 78578c517ff55ec4167050b2b626c31b43bee8d3 Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Mon, 24 Jul 2023 11:28:50 +0200
Subject: [PATCH 3/8] Add documentation for conditions in readme, add matching
 between condition and property key and add further unit tests for
 parseMessageFormat function

---
 Readme.md                        |  8 +++++++
 lib/utils.js                     |  2 +-
 test/lib/utils.internals.test.js | 38 +++++++++++++++++++++++++++++++-
 3 files changed, 46 insertions(+), 2 deletions(-)

diff --git a/Readme.md b/Readme.md
index d39082ba..528c0738 100644
--- a/Readme.md
+++ b/Readme.md
@@ -343,6 +343,14 @@ const levelPrettifier = logLevel => `LEVEL: ${levelColorize(logLevel)}`
 }
 ```
 
+In addition to this, if / end statement blocks can also be specified. Else statements and nested conditions are not supported.
+
+```js
+{
+  messageFormat: '{levelLabel} - {if pid}{pid}{end} - url:{req.url}'
+}
+```
+
 This option can also be defined as a `function` with this prototype:
 
 ```js
diff --git a/lib/utils.js b/lib/utils.js
index 9ad71c13..d585516b 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -787,7 +787,7 @@ function handleCustomlevelNamesOpts (cLevels) {
 function parseMessageFormat (messageFormat, log) {
   messageFormat = messageFormat.replace(/{if (.*?)}(.*?){end}/g, function (_, key, value) {
     const propertyValue = getPropertyValue(log, key)
-    if (propertyValue) {
+    if (propertyValue && value.includes(key)) {
       return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
     } else {
       return ''
diff --git a/test/lib/utils.internals.test.js b/test/lib/utils.internals.test.js
index 4dbb70cb..ed3161fc 100644
--- a/test/lib/utils.internals.test.js
+++ b/test/lib/utils.internals.test.js
@@ -228,7 +228,8 @@ tap.test('#parseMessageFormat', t => {
     level: 30,
     data1: {
       data2: 'bar'
-    }
+    },
+    msg: 'foo'
   }
 
   t.test('parseMessageFormat translates if / else statement to found property value', async t => {
@@ -236,6 +237,11 @@ tap.test('#parseMessageFormat', t => {
     t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}{end}', log), '{level} - bar')
   })
 
+  t.test('parseMessageFormat translates if / else statement to found property value and leave unmatched property key untouched', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2} ({msg}){end}', log), '{level} - bar ({msg})')
+  })
+
   t.test('parseMessageFormat removes unescaped if statements', async t => {
     const log = fastCopy(logData)
     t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}', log), '{level} - {data1.data2}')
@@ -246,5 +252,35 @@ tap.test('#parseMessageFormat', t => {
     t.equal(internals.parseMessageFormat('{level} - {data1.data2}{end}', log), '{level} - {data1.data2}')
   })
 
+  t.test('parseMessageFormat removes if / end blocks if existent condition key does not match existent property key', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level}{if msg}{data1.data2}{end}', log), '{level}')
+  })
+
+  t.test('parseMessageFormat removes if / end blocks if non-existent condition key does not match existent property key', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level}{if foo}{msg}{end}', log), '{level}')
+  })
+
+  t.test('parseMessageFormat removes if / end blocks if existent condition key does not match non-existent property key', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level}{if msg}{foo}{end}', log), '{level}')
+  })
+
+  t.test('parseMessageFormat removes if / end blocks if non-existent condition key does not match non-existent property key', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level}{if foo}{bar}{end}', log), '{level}')
+  })
+
+  t.test('parseMessageFormat removes if / end blocks if nested condition key does not match property key', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{level}{if data1.msg}{data1.data2}{end}', log), '{level}')
+  })
+
+  t.test('parseMessageFormat removes nested if / end statement blocks', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.parseMessageFormat('{if msg}{if data1.data2}{msg}{data1.data2}{end}{end}', log), 'foo{data1.data2}')
+  })
+
   t.end()
 })

From b6894c65367a19e0063b17a719ab4f40c75c6206 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20K=C3=B6ster?=
 <40566351+timlohse1104@users.noreply.github.com>
Date: Mon, 24 Jul 2023 11:57:09 +0200
Subject: [PATCH 4/8] Update docs of messageFormat with more fitting example

Co-authored-by: Matteo Collina <matteo.collina@gmail.com>
---
 Readme.md | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/Readme.md b/Readme.md
index 528c0738..62b23002 100644
--- a/Readme.md
+++ b/Readme.md
@@ -347,7 +347,7 @@ In addition to this, if / end statement blocks can also be specified. Else state
 
 ```js
 {
-  messageFormat: '{levelLabel} - {if pid}{pid}{end} - url:{req.url}'
+  messageFormat: '{levelLabel} - {if pid}{pid} - {end}url:{req.url}'
 }
 ```
 

From 8f224375215cac8b88dc390a5d18a3e833394f2e Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Mon, 24 Jul 2023 17:01:00 +0200
Subject: [PATCH 5/8] Renamed parseMessageFormat into interpretConditionals,
 add further interal unit test scenario, refactored interpretConditionals
 logic to be more readable and renamed internal unit tests to be more fitting

---
 lib/utils.js                     | 24 ++++++++--------
 test/lib/utils.internals.test.js | 47 ++++++++++++++++++--------------
 2 files changed, 39 insertions(+), 32 deletions(-)

diff --git a/lib/utils.js b/lib/utils.js
index d585516b..3a2204ad 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -43,7 +43,7 @@ module.exports.internals = {
   splitPropertyKey,
   createDate,
   isValidDate,
-  parseMessageFormat
+  interpretConditionals
 }
 
 /**
@@ -264,7 +264,7 @@ function prettifyLevel ({ log, colorizer = defaultColorizer, levelKey = LEVEL_KE
  */
 function prettifyMessage ({ log, messageFormat, messageKey = MESSAGE_KEY, colorizer = defaultColorizer, levelLabel = LEVEL_LABEL, levelKey = LEVEL_KEY, customLevels, useOnlyCustomProps }) {
   if (messageFormat && typeof messageFormat === 'string') {
-    const parsedMessageFormat = parseMessageFormat(messageFormat, log)
+    const parsedMessageFormat = interpretConditionals(messageFormat, log)
 
     const message = String(parsedMessageFormat).replace(
       /{([^{}]+)}/g,
@@ -784,15 +784,8 @@ function handleCustomlevelNamesOpts (cLevels) {
  *
  * @returns {string} The parsed messageFormat.
  */
-function parseMessageFormat (messageFormat, log) {
-  messageFormat = messageFormat.replace(/{if (.*?)}(.*?){end}/g, function (_, key, value) {
-    const propertyValue = getPropertyValue(log, key)
-    if (propertyValue && value.includes(key)) {
-      return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
-    } else {
-      return ''
-    }
-  })
+function interpretConditionals (messageFormat, log) {
+  messageFormat = messageFormat.replace(/{if (.*?)}(.*?){end}/g, replacer)
 
   // Remove unescaped if blocks
   messageFormat = messageFormat.replace(/{if (.*?)}/g, '')
@@ -800,4 +793,13 @@ function parseMessageFormat (messageFormat, log) {
   messageFormat = messageFormat.replace(/{end}/g, '')
 
   return messageFormat.replace(/\s+/g, ' ').trim()
+
+  function replacer (_, key, value) {
+    const propertyValue = getPropertyValue(log, key)
+    if (propertyValue && value.includes(key)) {
+      return value.replace(new RegExp('{' + key + '}', 'g'), propertyValue)
+    } else {
+      return ''
+    }
+  }
 }
diff --git a/test/lib/utils.internals.test.js b/test/lib/utils.internals.test.js
index ed3161fc..43919acb 100644
--- a/test/lib/utils.internals.test.js
+++ b/test/lib/utils.internals.test.js
@@ -223,7 +223,7 @@ tap.test('#getPropertyValue', t => {
   t.end()
 })
 
-tap.test('#parseMessageFormat', t => {
+tap.test('#interpretConditionals', t => {
   const logData = {
     level: 30,
     data1: {
@@ -232,54 +232,59 @@ tap.test('#parseMessageFormat', t => {
     msg: 'foo'
   }
 
-  t.test('parseMessageFormat translates if / else statement to found property value', async t => {
+  t.test('interpretConditionals translates if / else statement to found property value', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}{end}', log), '{level} - bar')
+    t.equal(internals.interpretConditionals('{level} - {if data1.data2}{data1.data2}{end}', log), '{level} - bar')
   })
 
-  t.test('parseMessageFormat translates if / else statement to found property value and leave unmatched property key untouched', async t => {
+  t.test('interpretConditionals translates if / else statement to found property value and leave unmatched property key untouched', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2} ({msg}){end}', log), '{level} - bar ({msg})')
+    t.equal(internals.interpretConditionals('{level} - {if data1.data2}{data1.data2} ({msg}){end}', log), '{level} - bar ({msg})')
   })
 
-  t.test('parseMessageFormat removes unescaped if statements', async t => {
+  t.test('interpretConditionals removes non-terminated if statements', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level} - {if data1.data2}{data1.data2}', log), '{level} - {data1.data2}')
+    t.equal(internals.interpretConditionals('{level} - {if data1.data2}{data1.data2}', log), '{level} - {data1.data2}')
   })
 
-  t.test('parseMessageFormat removes unescaped end statements', async t => {
+  t.test('interpretConditionals removes floating end statements', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level} - {data1.data2}{end}', log), '{level} - {data1.data2}')
+    t.equal(internals.interpretConditionals('{level} - {data1.data2}{end}', log), '{level} - {data1.data2}')
   })
 
-  t.test('parseMessageFormat removes if / end blocks if existent condition key does not match existent property key', async t => {
+  t.test('interpretConditionals removes floating end statements within translated if / end statements', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level}{if msg}{data1.data2}{end}', log), '{level}')
+    t.equal(internals.interpretConditionals('{level} - {if msg}({msg}){end}{end}', log), '{level} - (foo)')
   })
 
-  t.test('parseMessageFormat removes if / end blocks if non-existent condition key does not match existent property key', async t => {
+  t.test('interpretConditionals removes if / end blocks if existent condition key does not match existent property key', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level}{if foo}{msg}{end}', log), '{level}')
+    t.equal(internals.interpretConditionals('{level}{if msg}{data1.data2}{end}', log), '{level}')
   })
 
-  t.test('parseMessageFormat removes if / end blocks if existent condition key does not match non-existent property key', async t => {
+  t.test('interpretConditionals removes if / end blocks if non-existent condition key does not match existent property key', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level}{if msg}{foo}{end}', log), '{level}')
+    t.equal(internals.interpretConditionals('{level}{if foo}{msg}{end}', log), '{level}')
   })
 
-  t.test('parseMessageFormat removes if / end blocks if non-existent condition key does not match non-existent property key', async t => {
+  t.test('interpretConditionals removes if / end blocks if existent condition key does not match non-existent property key', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level}{if foo}{bar}{end}', log), '{level}')
+    t.equal(internals.interpretConditionals('{level}{if msg}{foo}{end}', log), '{level}')
   })
 
-  t.test('parseMessageFormat removes if / end blocks if nested condition key does not match property key', async t => {
+  t.test('interpretConditionals removes if / end blocks if non-existent condition key does not match non-existent property key', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{level}{if data1.msg}{data1.data2}{end}', log), '{level}')
+    t.equal(internals.interpretConditionals('{level}{if foo}{bar}{end}', log), '{level}')
   })
 
-  t.test('parseMessageFormat removes nested if / end statement blocks', async t => {
+  t.test('interpretConditionals removes if / end blocks if nested condition key does not match property key', async t => {
     const log = fastCopy(logData)
-    t.equal(internals.parseMessageFormat('{if msg}{if data1.data2}{msg}{data1.data2}{end}{end}', log), 'foo{data1.data2}')
+    t.equal(internals.interpretConditionals('{level}{if data1.msg}{data1.data2}{end}', log), '{level}')
+  })
+
+  t.test('interpretConditionals removes nested if / end statement blocks', async t => {
+    const log = fastCopy(logData)
+    t.equal(internals.interpretConditionals('{if msg}{if data1.data2}{msg}{data1.data2}{end}{end}', log), 'foo{data1.data2}')
   })
 
   t.end()

From 44ac4c342dff2793f28fa0ff7b3f7f55a10a6ca8 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Tim=20K=C3=B6ster?=
 <40566351+timlohse1104@users.noreply.github.com>
Date: Mon, 24 Jul 2023 23:08:08 +0200
Subject: [PATCH 6/8] Renamed comments to be more fitting

Co-authored-by: James Sumners <321201+jsumners@users.noreply.github.com>
---
 lib/utils.js | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/lib/utils.js b/lib/utils.js
index 3a2204ad..533578f4 100644
--- a/lib/utils.js
+++ b/lib/utils.js
@@ -787,9 +787,9 @@ function handleCustomlevelNamesOpts (cLevels) {
 function interpretConditionals (messageFormat, log) {
   messageFormat = messageFormat.replace(/{if (.*?)}(.*?){end}/g, replacer)
 
-  // Remove unescaped if blocks
+  // Remove non-terminated if blocks
   messageFormat = messageFormat.replace(/{if (.*?)}/g, '')
-  // Remove unescaped end blocks
+  // Remove floating end blocks
   messageFormat = messageFormat.replace(/{end}/g, '')
 
   return messageFormat.replace(/\s+/g, ' ').trim()

From 5e4f0f49378e31490c97bd43517567fb2e6985b5 Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Tue, 25 Jul 2023 16:02:19 +0200
Subject: [PATCH 7/8] Add hideMetadata option, add unit tests and updated docs

---
 Readme.md          |  2 ++
 bin.js             |  3 ++-
 index.js           | 58 +++++++++++++++++++++++++---------------------
 test/basic.test.js | 20 ++++++++++++++++
 test/cli.test.js   | 13 +++++++++++
 5 files changed, 68 insertions(+), 28 deletions(-)

diff --git a/Readme.md b/Readme.md
index 62b23002..aae90d91 100644
--- a/Readme.md
+++ b/Readme.md
@@ -100,6 +100,7 @@ node app.js | pino-pretty
 - `--hideObject` (`-H`): Hide objects from output (but not error object)
 - `--singleLine` (`-S`): Print each log message on a single line (errors will still be multi-line)
 - `--config`: Specify a path to a config file containing the pino-pretty options.  pino-pretty will attempt to read from a `.pino-prettyrc` in your current directory (`process.cwd`) if not specified
+- `--hideMetadata` (`-M`): Hide Metadata (e.g. `timestamp` and `level`) in the beginning of each log line
 
 <a id="integration"></a>
 ## Programmatic Integration
@@ -258,6 +259,7 @@ The options accepted have keys corresponding to the options described in [CLI Ar
   levelLabel: 'levelLabel', // --levelLabel
   minimumLevel: 'info', // --minimumLevel
   useOnlyCustomProps: true, // --useOnlyCustomProps
+  hideMetadata: true, // --hideMetadata
   // The file or file descriptor (1 is stdout) to write to
   destination: 1,
 
diff --git a/bin.js b/bin.js
index 3e18d434..051bfe09 100644
--- a/bin.js
+++ b/bin.js
@@ -58,7 +58,8 @@ let opts = minimist(process.argv, {
     ignore: 'i',
     include: 'I',
     hideObject: 'H',
-    singleLine: 'S'
+    singleLine: 'S',
+    hideMetadata: 'M'
   },
   default: {
     messageKey: DEFAULT_VALUE,
diff --git a/index.js b/index.js
index 41eb7602..84973fc3 100644
--- a/index.js
+++ b/index.js
@@ -49,7 +49,8 @@ const defaultOptions = {
   hideObject: false,
   ignore: 'hostname',
   include: undefined,
-  singleLine: false
+  singleLine: false,
+  hideMetadata: false
 }
 
 function prettyFactory (options) {
@@ -127,39 +128,42 @@ function prettyFactory (options) {
       log = filterLog({ log, ignoreKeys, includeKeys })
     }
 
-    const prettifiedLevel = prettifyLevel({ log, colorizer, levelKey, prettifier: customPrettifiers.level, ...customProps })
-    const prettifiedMetadata = prettifyMetadata({ log, prettifiers: customPrettifiers })
-    const prettifiedTime = prettifyTime({ log, translateFormat: opts.translateTime, timestampKey, prettifier: customPrettifiers.time })
-
     let line = ''
-    if (opts.levelFirst && prettifiedLevel) {
-      line = `${prettifiedLevel}`
-    }
 
-    if (prettifiedTime && line === '') {
-      line = `${prettifiedTime}`
-    } else if (prettifiedTime) {
-      line = `${line} ${prettifiedTime}`
-    }
+    if (!opts.hideMetadata) {
+      const prettifiedLevel = prettifyLevel({ log, colorizer, levelKey, prettifier: customPrettifiers.level, ...customProps })
+      const prettifiedMetadata = prettifyMetadata({ log, prettifiers: customPrettifiers })
+      const prettifiedTime = prettifyTime({ log, translateFormat: opts.translateTime, timestampKey, prettifier: customPrettifiers.time })
 
-    if (!opts.levelFirst && prettifiedLevel) {
-      if (line.length > 0) {
-        line = `${line} ${prettifiedLevel}`
-      } else {
-        line = prettifiedLevel
+      if (opts.levelFirst && prettifiedLevel) {
+        line = `${prettifiedLevel}`
       }
-    }
 
-    if (prettifiedMetadata) {
-      if (line.length > 0) {
-        line = `${line} ${prettifiedMetadata}:`
-      } else {
-        line = prettifiedMetadata
+      if (prettifiedTime && line === '') {
+        line = `${prettifiedTime}`
+      } else if (prettifiedTime) {
+        line = `${line} ${prettifiedTime}`
+      }
+
+      if (!opts.levelFirst && prettifiedLevel) {
+        if (line.length > 0) {
+          line = `${line} ${prettifiedLevel}`
+        } else {
+          line = prettifiedLevel
+        }
       }
-    }
 
-    if (line.endsWith(':') === false && line !== '') {
-      line += ':'
+      if (prettifiedMetadata) {
+        if (line.length > 0) {
+          line = `${line} ${prettifiedMetadata}:`
+        } else {
+          line = prettifiedMetadata
+        }
+      }
+
+      if (line.endsWith(':') === false && line !== '') {
+        line += ':'
+      }
     }
 
     if (prettifiedMessage !== undefined) {
diff --git a/test/basic.test.js b/test/basic.test.js
index 9986811c..e303cb18 100644
--- a/test/basic.test.js
+++ b/test/basic.test.js
@@ -118,6 +118,26 @@ test('basic prettifier tests', (t) => {
     log.info('foo')
   })
 
+  t.test('can hide date and level', (t) => {
+    t.plan(1)
+    const destination = new Writable({
+      write (formatted, enc, cb) {
+        t.equal(
+          formatted.toString(),
+          'foo\n'
+        )
+        cb()
+      }
+    })
+    const pretty = pinoPretty({
+      destination,
+      hideMetadata: true,
+      colorize: false
+    })
+    const log = pino({}, pretty)
+    log.info('foo')
+  })
+
   t.test('can print message key value when its a string', (t) => {
     t.plan(1)
     const pretty = prettyFactory()
diff --git a/test/cli.test.js b/test/cli.test.js
index 9b24a078..f1d264af 100644
--- a/test/cli.test.js
+++ b/test/cli.test.js
@@ -37,6 +37,19 @@ test('cli', (t) => {
     })
   })
 
+  ;['--hideMetadata', '-M'].forEach((optionName) => {
+    t.test(`hides epoch, level and metadata via ${optionName}`, (t) => {
+      t.plan(1)
+      const child = spawn(process.argv[0], [bin, optionName], { env })
+      child.on('error', t.threw)
+      child.stdout.on('data', (data) => {
+        t.equal(data.toString(), 'hello world\n')
+      })
+      child.stdin.write(logLine)
+      t.teardown(() => child.kill())
+    })
+  })
+
   ;['--translateTime', '-t'].forEach((optionName) => {
     t.test(`translates time to default format via ${optionName}`, (t) => {
       t.plan(1)

From 8a4066f0fcb5084731d43f416e794dc1400a7f88 Mon Sep 17 00:00:00 2001
From: timlohse1104 <tim-lohse@gmx.de>
Date: Tue, 1 Aug 2023 00:01:13 +0200
Subject: [PATCH 8/8] Refactor nested condition in seperate function

---
 index.js | 74 +++++++++++++++++++++++++++++++-------------------------
 1 file changed, 41 insertions(+), 33 deletions(-)

diff --git a/index.js b/index.js
index 84973fc3..566b04a2 100644
--- a/index.js
+++ b/index.js
@@ -131,39 +131,7 @@ function prettyFactory (options) {
     let line = ''
 
     if (!opts.hideMetadata) {
-      const prettifiedLevel = prettifyLevel({ log, colorizer, levelKey, prettifier: customPrettifiers.level, ...customProps })
-      const prettifiedMetadata = prettifyMetadata({ log, prettifiers: customPrettifiers })
-      const prettifiedTime = prettifyTime({ log, translateFormat: opts.translateTime, timestampKey, prettifier: customPrettifiers.time })
-
-      if (opts.levelFirst && prettifiedLevel) {
-        line = `${prettifiedLevel}`
-      }
-
-      if (prettifiedTime && line === '') {
-        line = `${prettifiedTime}`
-      } else if (prettifiedTime) {
-        line = `${line} ${prettifiedTime}`
-      }
-
-      if (!opts.levelFirst && prettifiedLevel) {
-        if (line.length > 0) {
-          line = `${line} ${prettifiedLevel}`
-        } else {
-          line = prettifiedLevel
-        }
-      }
-
-      if (prettifiedMetadata) {
-        if (line.length > 0) {
-          line = `${line} ${prettifiedMetadata}:`
-        } else {
-          line = prettifiedMetadata
-        }
-      }
-
-      if (line.endsWith(':') === false && line !== '') {
-        line += ':'
-      }
+      line += createLineMetadata()
     }
 
     if (prettifiedMessage !== undefined) {
@@ -210,6 +178,46 @@ function prettyFactory (options) {
     }
 
     return line
+
+    function createLineMetadata () {
+      let lineMetadata = ''
+
+      const prettifiedLevel = prettifyLevel({ log, colorizer, levelKey, prettifier: customPrettifiers.level, ...customProps })
+      const prettifiedMetadata = prettifyMetadata({ log, prettifiers: customPrettifiers })
+      const prettifiedTime = prettifyTime({ log, translateFormat: opts.translateTime, timestampKey, prettifier: customPrettifiers.time })
+
+      if (opts.levelFirst && prettifiedLevel) {
+        lineMetadata = `${prettifiedLevel}`
+      }
+
+      if (prettifiedTime && lineMetadata === '') {
+        lineMetadata = `${prettifiedTime}`
+      } else if (prettifiedTime) {
+        lineMetadata = `${lineMetadata} ${prettifiedTime}`
+      }
+
+      if (!opts.levelFirst && prettifiedLevel) {
+        if (lineMetadata.length > 0) {
+          lineMetadata = `${lineMetadata} ${prettifiedLevel}`
+        } else {
+          lineMetadata = prettifiedLevel
+        }
+      }
+
+      if (prettifiedMetadata) {
+        if (lineMetadata.length > 0) {
+          lineMetadata = `${lineMetadata} ${prettifiedMetadata}:`
+        } else {
+          lineMetadata = prettifiedMetadata
+        }
+      }
+
+      if (lineMetadata.endsWith(':') === false && lineMetadata !== '') {
+        lineMetadata += ':'
+      }
+
+      return lineMetadata
+    }
   }
 }