refactor(formatter): Move general utility functions from YScope formatter to global utilities.

src/services/formatters/YscopeFormatter/FieldFormatters/RoundFormatter.ts

@@ -1,7 +1,7 @@
 import {Nullable} from "../../../../typings/common";
 import {YscopeFieldFormatter} from "../../../../typings/formatters";
 import {JsonValue} from "../../../../typings/js";
-import {jsonValueToString} from "../utils";
+import {jsonValueToString} from "../../../../utils/formatters";
 
 
 /**

src/services/formatters/YscopeFormatter/index.ts

@@ -9,10 +9,12 @@ import {
 } from "../../../typings/formatters";
 import {LogEvent} from "../../../typings/logs";
 import {
-    getFormattedField,
     jsonValueToString,
     removeEscapeCharacters,
     replaceDoubleBacklash,
+} from "../../../utils/formatters";
+import {
+    getFormattedField,
     splitFieldPlaceholder,
     YSCOPE_FIELD_FORMATTER_MAP,
 } from "./utils";
@@ -29,8 +31,8 @@ class YscopeFormatter implements Formatter {
 
     constructor (options: FormatterOptionsType) {
         if (options.formatString.includes(REPLACEMENT_CHARACTER)) {
-            console.warn("Unicode replacement character `U+FFFD` is found in Decoder Format" +
-            ' String, which will appear as "\\".');
+            console.warn("Unicode replacement character `U+FFFD` found in format string; " +
+                         "it will be replaced with \"\\\"");
         }
 
         this.#processedFormatString = replaceDoubleBacklash(options.formatString);
@@ -62,9 +64,9 @@ class YscopeFormatter implements Formatter {
     }
 
     /**
-     * Parses field placeholders in format string. For each field placeholder, creates a
-     * corresponding `YscopeFieldFormatter` using the placeholder's field name, formatter type,
-     * and formatter options. Each `YscopeFieldFormatter` is then stored on the
+     * Parses field placeholders in format string. For each field, creates a corresponding
+     * `YscopeFieldPlaceholder` using the placeholder's field name, formatter type,
+     * and formatter options. Each `YscopeFieldPlaceholder` is then stored on the
      * class-level array `#fieldPlaceholders`.
      *
      * @throws Error if `FIELD_PLACEHOLDER_REGEX` does not contain a capture group.

src/services/formatters/YscopeFormatter/utils.ts

@@ -1,15 +1,15 @@
 import {Nullable} from "../../../typings/common";
 import {
     COLON_REGEX,
-    DOUBLE_BACKSLASH,
     PERIOD_REGEX,
-    REPLACEMENT_CHARACTER,
-    SINGLE_BACKSLASH,
     YscopeFieldFormatterMap,
     YscopeFieldPlaceholder,
 } from "../../../typings/formatters";
-import {JsonValue} from "../../../typings/js";
 import {LogEvent} from "../../../typings/logs";
+import {
+    jsonValueToString,
+    removeEscapeCharacters,
+} from "../../../utils/formatters";
 import {getNestedJsonValue} from "../../../utils/js";
 import RoundFormatter from "./FieldFormatters/RoundFormatter";
 import TimestampFormatter from "./FieldFormatters/TimestampFormatter";
@@ -23,71 +23,6 @@ const YSCOPE_FIELD_FORMATTER_MAP: YscopeFieldFormatterMap = Object.freeze({
     round: RoundFormatter,
 });
 
-
-/**
- * Removes all backslashes from a string. Purpose is to remove escape character in front of brace
- * and colon characters.
- *
- * @param str
- * @return Modified string.
- */
-const removeBackslash = (str: string): string => {
-    return str.replaceAll(SINGLE_BACKSLASH, "");
-};
-
-/**
- * Replaces all replacement characters in format string with a single backslash. Purpose is to
- * remove, albeit indirectly through intermediate replacement character, escape character in
- * front of a backslash character.
- *
- * @param str
- * @return Modified string.
- */
-const replaceReplacementCharacter = (str: string): string => {
-    return str.replaceAll(REPLACEMENT_CHARACTER, "\\");
-};
-
-/**
- * Removes escape characters from a string.
- *
- * @param str
- * @return Modified string.
- */
-const removeEscapeCharacters = (str: string): string => {
-    // `removeBackslash()`, which removes all  backlashes, is called before
-    // `replaceReplacementCharacter()` to prevent removal of escaped backslashes.
-    return replaceReplacementCharacter(removeBackslash(str));
-};
-
-/**
- * Replaces all escaped backslashes in format string with replacement character.
- * Replacement character is a rare character that is unlikely to be in user format string.
- * Writing regex to distinguish between a single escape character ("\") and an escaped backslash
- * ("\\") is challenging especially when they are in series. It is simpler to just replace
- * escaped backslashes with a rare character and add them back after parsing field placeholder
- * with regex is finished.
- *
- * @param formatString
- * @return Modified format string.
- */
-const replaceDoubleBacklash = (formatString: string): string => {
-    return formatString.replaceAll(DOUBLE_BACKSLASH, REPLACEMENT_CHARACTER);
-};
-
-
-/**
- * Converts a JSON value to its string representation.
- *
- * @param input
- * @return
- */
-const jsonValueToString = (input: JsonValue | undefined): string => {
-    // Behaviour is different for `undefined`.
-    return "object" === typeof input ?
-        JSON.stringify(input) :
-        String(input);
-};
-
 /**
  * Gets a formatted field. Specifically, retrieves a field from a log event using a placeholder's
  * `fieldNameKeys`. The field is then formatted using the placeholder's `fieldFormatter`.
@@ -175,9 +110,6 @@ const splitFieldPlaceholder = (placeholderString: string): {
 
 export {
     getFormattedField,
-    jsonValueToString,
-    removeEscapeCharacters,
-    replaceDoubleBacklash,
     splitFieldPlaceholder,
     YSCOPE_FIELD_FORMATTER_MAP,
 };

src/utils/formatters.ts

@@ -0,0 +1,77 @@
+import {
+    DOUBLE_BACKSLASH,
+    REPLACEMENT_CHARACTER,
+    SINGLE_BACKSLASH,
+} from "../typings/formatters";
+import {JsonValue} from "../typings/js";
+
+
+/**
+ * Removes all backslashes from a string. Purpose is to remove escape character preceding
+ * other reserved characters.
+ *
+ * @param str
+ * @return Modified string.
+ */
+const removeBackslash = (str: string): string => {
+    return str.replaceAll(SINGLE_BACKSLASH, "");
+};
+
+/**
+ * Replaces all replacement characters with a single backslash. Purpose is to remove, albeit
+ * indirectly through intermediate replacement character, escape character in front of a backslash
+ * character.
+ *
+ * @param str
+ * @return Modified string.
+ */
+const replaceReplacementCharacter = (str: string): string => {
+    return str.replaceAll(REPLACEMENT_CHARACTER, "\\");
+};
+
+/**
+ * Removes escape characters from a string.
+ *
+ * @param str
+ * @return Modified string.
+ */
+const removeEscapeCharacters = (str: string): string => {
+    // `removeBackslash()`, which removes all  backlashes, is called before
+    // `replaceReplacementCharacter()` to prevent removal of escaped backslashes.
+    return replaceReplacementCharacter(removeBackslash(str));
+};
+
+/**
+ * Replaces all escaped backslashes with replacement character. Replacement character is a rare
+ * character that is unlikely to be in user string. Writing regex to distinguish between
+ * a single escape character ("\") and an escaped backslash ("\\") is challenging especially
+ * when they are in series. It is simpler to just replace escaped backslashes with a rare character
+ * and add them back after parsing user string with regex is finished.
+ *
+ * @param string
+ * @return Modified string.
+ */
+const replaceDoubleBacklash = (string: string): string => {
+    return string.replaceAll(DOUBLE_BACKSLASH, REPLACEMENT_CHARACTER);
+};
+
+
+/**
+ * Converts a JSON value to its string representation.
+ *
+ * @param input
+ * @return
+ */
+const jsonValueToString = (input: JsonValue | undefined): string => {
+    // Behaviour is different for `undefined`.
+    return "object" === typeof input ?
+        JSON.stringify(input) :
+        String(input);
+};
+
+
+export {
+    jsonValueToString,
+    removeEscapeCharacters,
+    replaceDoubleBacklash,
+};