Coercing filter and format arg options with args

dependency-tree.ts

@@ -3,6 +3,12 @@ import path from "path";
 
 import { hideBin } from "yargs/helpers";
 
+
+
+type FormatValue = "tree" | "csv";
+type Format = { header: string, apply: (node: PackageLockTree, parents: string[]) => string }
+type FilterValue = "none" | "oracle";
+
 const args = yargs(hideBin(process.argv))
     .option("package", {
         type: "string",
@@ -10,19 +16,34 @@ const args = yargs(hideBin(process.argv))
         require: true
     })
     .option("format", {
-        choices: ["tree", "csv"],
-        demandOption: true,
-        default: "tree"
+        describe: "Possible values are 'tree' and 'csv'",
+        default: "tree",
+        coerce: (value: FormatValue): Format =>
+            value === "tree"
+                ? {
+                    header: "",
+                    apply: (node: PackageLockTree, parents: string[]) =>
+                        `${"  ".repeat(parents.length)}${node.value.name}@${node.value.version}${node.value.dev ? " (dev)" : ""}`
+                }
+                : {
+                    header: "name,version,root,parent,type",
+                    apply: (node: PackageLockTree, parents: string[]) =>
+                        `${node.value.name},${node.value.version},${parents[0] ?? ""},${parents[parents.length - 1] ?? ""},${node.value.dev ? "devDependency" : "dependency"}`
+                }
     })
     .option("filter", {
-        choices: ["none", "oracle"],
-        demandOption: true,
-        default: "none"
+        describe: "Possible values are 'none' and 'oracle'",
+        default: "none",
+        coerce: (value: FilterValue) =>
+            value === "oracle"
+                ? (node: PackageLockTree, parents: string[]) => (parents.length === 0 && !node.value.name.startsWith("@os")) || (!node.value.name.startsWith("@o") && parents.length > 1 && parents.every(p => p.startsWith("@os")))
+                : (node: PackageLockTree, parents: string[]) => true
     })
     .help()
     .argv;
 
 
+
 interface Dictionary<T> {
     [index: string]: T
 }
@@ -76,19 +97,22 @@ const constructDepTree = (packageName: string, context: PackageLockDependencies,
     };
 }
 
-const displayDepTree = (format: (node: PackageLockTree, parents: string[]) => string) =>
-    (filter: (node: PackageLockTree, parents: string[]) => boolean) =>
+const displayDepTree = (format: Format) => {
+    console.log(format.header);
+    return (filter: (node: PackageLockTree, parents: string[]) => boolean) =>
         (tree: PackageLockTree) => {
             const iter = (tree: PackageLockTree, stack: string[] = []) => {
                 if (filter(tree, stack)) {
-                    console.log(format(tree, stack));
+                    console.log(format.apply(tree, stack));
                 }
                 if (tree.type === "node") {
                     tree.children.forEach(t => iter(t, [...stack, `${tree.value.name}@${tree.value.version}`]))
                 }
             }
             iter(tree);
-        }
+        };
+}
+
 
 
 Promise.all<Package, PackageLock>([
@@ -99,16 +123,7 @@ Promise.all<Package, PackageLock>([
         const dependencyTree = Object.keys(json.dependencies)
             .concat(Object.keys(json.devDependencies ?? {}))
             .map(depName => constructDepTree(depName, jsonLock.dependencies));
-        if (args.format === "csv") {
-            console.log("name,version,root,parent,type");
-        }
-        const format = args.format === "tree"
-            ? (node: PackageLockTree, parents: string[]) => `${"  ".repeat(parents.length)}${node.value.name}@${node.value.version}${node.value.dev ? " (dev)" : ""}`
-            : (node: PackageLockTree, parents: string[]) => `${node.value.name},${node.value.version},${parents[0] ?? ""},${parents[parents.length - 1] ?? ""},${node.value.dev ? "devDependency" : "dependency"}`;
-        const filter = args.filter === "oracle"
-            ? (node: PackageLockTree, parents: string[]) => (parents.length === 0 && !node.value.name.startsWith("@os")) || (!node.value.name.startsWith("@o") && parents.length > 1 && parents.every(p => p.startsWith("@os")))
-            : (node: PackageLockTree, parents: string[]) => true;
-        const display = displayDepTree(format)(filter);
+        const display = displayDepTree(args.format)(args.filter);
         dependencyTree.forEach(t => display(t));
     })
     .catch(reson => {