fix(cmn): proper snake case for metric names

Fixes the snake case function for metric names to properly account for
strings which include "L1" or "L2". Normally these would be split into
"L_1" and "L_2" respectively, but we want to join these since they're
quite common and "L_1" looks silly.

.changeset/selfish-paws-reply.md

+---
+'@eth-optimism/common-ts': patch
+---
+
+Update metric names to include proper snake_case for strings that include "L1" or "L2"

packages/common-ts/src/base-service/base-service-v2.ts

@@ -107,19 +107,28 @@ export abstract class BaseServiceV2<
       params.loopIntervalMs !== undefined ? params.loopIntervalMs : 0
     this.state = {} as TServiceState
 
+    /**
+     * Special snake_case function which accounts for the common strings "L1" and "L2" which would
+     * normally be split into "L_1" and "L_2" by the snake_case function.
+     *
+     * @param str String to convert to snake_case.
+     * @returns snake_case string.
+     */
+    const opSnakeCase = (str: string) => {
+      const reg = /l_1|l_2/g
+      const repl = str.includes('l1') ? 'l1' : 'l2'
+      return snakeCase(str).replace(reg, repl)
+    }
+
     // Use commander as a way to communicate info about the service. We don't actually *use*
     // commander for anything besides the ability to run `ts-node ./service.ts --help`.
     const program = new Command()
-    const reg = /L_1|L_2/g
     for (const [optionName, optionSpec] of Object.entries(params.optionsSpec)) {
-      const repl = optionName.includes('l1') ? 'L1' : 'L2'
       program.addOption(
         new Option(`--${optionName.toLowerCase()}`, `${optionSpec.desc}`).env(
-          `${snakeCase(
+          `${opSnakeCase(
             params.name.replace(/-/g, '_')
-          ).toUpperCase()}__${snakeCase(optionName)
-            .toUpperCase()
-            .replace(reg, repl)}`
+          ).toUpperCase()}__${opSnakeCase(optionName).toUpperCase()}`
         )
       )
     }
@@ -140,7 +149,7 @@ export abstract class BaseServiceV2<
       'after',
       `\nMetrics:\n${Object.entries(params.metricsSpec)
         .map(([metricName, metricSpec]) => {
-          const parsedName = snakeCase(metricName)
+          const parsedName = opSnakeCase(metricName)
           return `  ${parsedName}${' '.repeat(
             longestMetricNameLength - parsedName.length + 2
           )}${metricSpec.desc} (type: ${metricSpec.type.name})`
@@ -187,7 +196,7 @@ export abstract class BaseServiceV2<
     this.metrics = Object.keys(params.metricsSpec || {}).reduce((acc, key) => {
       const spec = params.metricsSpec[key]
       acc[key] = new spec.type({
-        name: `${snakeCase(params.name)}_${snakeCase(key)}`,
+        name: `${opSnakeCase(params.name)}_${opSnakeCase(key)}`,
         help: spec.desc,
         labelNames: spec.labels || [],
       })