lint: begin linting concept exercise config.json

src/helpers.nim

@@ -16,3 +16,9 @@ proc getSortedSubdirs*(dir: string): seq[string] =
     if kind == pcDir:
       result.add path
   sort result
+
+template writeError*(description: string, details: string) =
+  stdout.styledWriteLine(fgRed, description & ":")
+  stdout.writeLine(details)
+  stdout.write "\n"
+  result = false

src/lint/concept_exercises.nim

@@ -0,0 +1,37 @@
+import std/[json, os, terminal]
+import ".."/helpers
+import "."/validators
+
+proc isValidAuthorOrContributor(data: JsonNode, key: string, path: string): bool =
+  checkObject(key)
+  checkStringKey("github_username", isRequired = true)
+  checkStringKey("exercism_username", isRequired = false)
+
+template isValidFiles(data: JsonNode, context, path: string) =
+  checkObject(context)
+  checkArrayOfStrings(context, "solution", isRequired = true)
+  checkArrayOfStrings(context, "test", isRequired = true)
+  checkArrayOfStrings(context, "exemplar", isRequired = true)
+
+proc isValidConceptExerciseConfig(data: JsonNode, path: string): bool =
+  checkObject("root")
+  checkArrayOf("authors", isValidAuthorOrContributor, isRequired = true)
+  checkArrayOf("contributors", isValidAuthorOrContributor, isRequired = false)
+  checkArrayOfStrings("", "forked_from", isRequired = false)
+  isValidFiles(data, "files", path)
+  checkStringKey("language_versions", isRequired = false)
+
+proc isEveryConceptExerciseConfigValid*(trackDir: string): bool =
+  let conceptExercisesDir = trackDir / "exercises" / "concept"
+  result = true
+  if dirExists(conceptExercisesDir):
+    for exerciseDir in getSortedSubdirs(conceptExercisesDir):
+      let configPath = exerciseDir / ".meta" / "config.json"
+      let j =
+        try:
+          parseFile(configPath)
+        except:
+          writeError("JSON parsing error", getCurrentExceptionMsg())
+          continue
+      if not isValidConceptExerciseConfig(j, configPath):
+        result = false

src/lint/lint.nim

@@ -1,11 +1,6 @@
 import std/[json, os, strformat, terminal]
 import ".."/[cli, helpers]
-
-template writeError(description: string, details: string) =
-  stdout.styledWriteLine(fgRed, description & ":")
-  stdout.writeLine(details)
-  stdout.write "\n"
-  result = false
+import "."/concept_exercises
 
 proc isValidTrackConfig(trackDir: string): bool =
   result = true
@@ -64,12 +59,14 @@ proc lint*(conf: Conf) =
   let b1 = isValidTrackConfig(trackDir)
   let b2 = conceptExerciseFilesExist(trackDir)
   let b3 = conceptFilesExist(trackDir)
+  let b4 = isEveryConceptExerciseConfigValid(trackDir)
 
-  if b1 and b2 and b3:
+  if b1 and b2 and b3 and b4:
     echo """
 Basic linting finished successfully:
 - config.json exists and is valid JSON
 - Every concept exercise has the required .md files and a .meta/config.json file
-- Every concept has the required .md files and links.json file"""
+- Every concept has the required .md files and links.json file
+- Every concept exercise .meta/config.json file is valid"""
   else:
     quit(1)

src/lint/validators.nim

@@ -0,0 +1,54 @@
+import std/json
+import ".."/helpers
+
+template checkObject*(key: string) =
+  if data.kind != JObject:
+    writeError("Not an object: " & key, path)
+    return false
+  result = true
+
+template checkStringKey*(key: string, isRequired: bool) =
+  if data.hasKey(key):
+    if data[key].kind == JString:
+      if data[key].getStr().len == 0:
+        writeError("String is zero-length: " & key, path)
+    else:
+      writeError("Not a string: `" & key & ": " & $data[key] & "`", path)
+  elif isRequired:
+    writeError("Missing key: " & key, path)
+
+template checkArrayOfStrings*(context, key: string; isRequired: bool) =
+  if data.hasKey(key):
+    if data[key].kind == JArray:
+      if data[key].len == 0:
+        writeError("Array is empty: " & key, path)
+      else:
+        for item in data[key]:
+          if item.kind != JString:
+            result = false
+            # writeError("Array contains item with the wrong kind" & key & $item, path)
+            # break
+          elif item.getStr().len == 0:
+            writeError("Array contains zero-length string: " & key, path)
+    else:
+      writeError("Not an array: " & key, path)
+  elif isRequired:
+    writeError("Missing key: " & context & "." & key, path)
+
+template checkArrayOf*(key: string,
+                      call: proc(d: JsonNode, key: string, path: string): bool,
+                      isRequired: bool) =
+  if data.hasKey(key):
+    if data[key].kind == JArray:
+      if data[key].len == 0:
+        writeError("Array is empty: " & key, path)
+      else:
+        for item in data[key]:
+          if not call(item, key, path):
+            result = false
+            # writeError("Item in array fails check: " & $item, path)
+            # break
+    else:
+      writeError("Not an array: " & key, path)
+  elif isRequired:
+    writeError("Missing key: " & key, path)