plan a charm file resource built by local script

src/build.ts

@@ -137,12 +137,15 @@ interface BuildDockerImageParams {
 
 async function buildFileResource(plan: BuildPlan): Promise<void> {
   core.startGroup(`Build resource {plan.name}`)
-  await exec.exec(`./build-${plan.name}.sh`, [plan.source_file], {
+  if (!plan.build_target) {
+    throw new Error('build_target is required for file resources')
+  }
+  await exec.exec(`./${plan.source_file}`, [plan.build_target], {
     cwd: plan.source_directory
   })
   core.endGroup()
   const resourceFiles = await (
-    await glob.create(path.join(plan.source_directory, plan.source_file))
+    await glob.create(path.join(plan.source_directory, plan.build_target))
   ).glob()
   const artifact = new DefaultArtifactClient()
   const manifestFile = path.join(plan.source_directory, 'manifest.json')

src/model.ts

@@ -11,6 +11,7 @@ export interface BuildPlan {
   name: string
   source_file: string
   source_directory: string
+  build_target: string | undefined
   output_type: 'file' | 'registry'
   output: string
 }

src/plan.ts

@@ -71,6 +71,7 @@ async function planBuildCharm(
       name,
       source_file: file,
       source_directory: path.dirname(file),
+      build_target: undefined,
       output_type: 'file',
       output: sanitizeArtifactName(`${id}__build__output__charm__${name}`)
     }
@@ -97,6 +98,7 @@ async function planBuildRock(
       name,
       source_file: file,
       source_directory: path.dirname(file),
+      build_target: undefined,
       output_type: outputType,
       output: sanitizeArtifactName(`${id}__build__output__rock__${name}`)
     }
@@ -119,6 +121,7 @@ async function planBuildDockerImage(
       name,
       source_file: file,
       source_directory: path.dirname(file),
+      build_target: undefined,
       output_type: outputType,
       output: sanitizeArtifactName(
         `${id}__build__output__docker-image__${name}`
@@ -181,7 +184,8 @@ async function planBuildFileResource(
           acc.push({
             type: 'file',
             name: resourceName,
-            source_file: resource.filename,
+            source_file: `build-${resourceName}.sh`,
+            build_target: resource.filename,
             source_directory: parent,
             output_type: 'file',
             output: sanitizeArtifactName(