BREAKING(encoding/csv): make column argument optional (#2168)

denoland · Sep 7, 2022 · d3b14b2 · d3b14b2
1 parent 3d802b2
commit d3b14b2
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Showing 3 changed files with 106 additions and 88 deletions.
diff --git a/encoding/README.md b/encoding/README.md
@@ -227,7 +227,7 @@ let columns: Column[] = [
   "age",
 ];
 
-console.log(await stringify(data, columns));
+console.log(await stringify(data, { columns }));
 // first,age
 // Rick,70
 // Morty,14
@@ -245,7 +245,7 @@ columns = [
   },
 ];
 
-console.log(await stringify(data, columns, { separator: "\t" }));
+console.log(await stringify(data, { separator: "\t", columns }));
 // name	is_adult
 // Rick Sanchez	true
 // Morty Smith	false

diff --git a/encoding/csv.ts b/encoding/csv.ts
@@ -111,22 +111,36 @@ async function getValuesFromItem(
 ): Promise<unknown[]> {
   const values: unknown[] = [];
 
-  for (const column of normalizedColumns) {
-    let value: unknown = item;
-
-    for (const prop of column.prop) {
-      if (typeof value !== "object" || value === null) continue;
-      if (Array.isArray(value)) {
-        if (typeof prop === "number") value = value[prop];
-        else {
-          throw new StringifyError('Property accessor is not of type "number"');
-        }
-      } // I think this assertion is safe. Confirm?
-      else value = (value as ObjectWithStringPropertyKeys)[prop];
-    }
+  if (normalizedColumns.length) {
+    for (const column of normalizedColumns) {
+      let value: unknown = item;
+
+      for (const prop of column.prop) {
+        if (typeof value !== "object" || value === null) continue;
+        if (Array.isArray(value)) {
+          if (typeof prop === "number") value = value[prop];
+          else {
+            throw new StringifyError(
+              'Property accessor is not of type "number"',
+            );
+          }
+        } // I think this assertion is safe. Confirm?
+        else value = (value as ObjectWithStringPropertyKeys)[prop];
+      }
 
-    if (typeof column.fn === "function") value = await column.fn(value);
-    values.push(value);
+      if (typeof column.fn === "function") value = await column.fn(value);
+      values.push(value);
+    }
+  } else {
+    if (Array.isArray(item)) {
+      values.push(...item);
+    } else if (typeof item === "object") {
+      throw new StringifyError(
+        "No property accessor function was provided for object",
+      );
+    } else {
+      values.push(item);
+    }
   }
 
   return values;
@@ -145,23 +159,17 @@ async function getValuesFromItem(
 export type StringifyOptions = {
   headers?: boolean;
   separator?: string;
+  columns?: Column[];
 };
 
 /**
  * @param data The array of objects to encode
- * @param columns Array of values specifying which data to include in the output
  * @param options Output formatting options
  */
 export async function stringify(
   data: DataItem[],
-  columns: Column[],
-  options: StringifyOptions = {},
+  { headers = true, separator: sep = ",", columns = [] }: StringifyOptions = {},
 ): Promise<string> {
-  const { headers, separator: sep } = {
-    headers: true,
-    separator: ",",
-    ...options,
-  };
   if (sep.includes(QUOTE) || sep.includes(NEWLINE)) {
     const message = [
       "Separator cannot include the following strings:",