taler-typescript-core

commit 5bbe5b792e28954a76dae0aa38f16bf9da948e03
parent 03c36d57c23f6d21bbfbe46910577a2960035761
Author: Florian Dold <dold@taler.net>
Date:   Tue, 21 Jul 2026 20:03:10 +0200

util: escape, quote and preserve names when writing a config back

A newline in a value emitted further configuration lines, leading and
trailing whitespace was lost for want of quoting, and section and option
names were upper-cased over the author's own file.

Diffstat:
M
packages/taler-util/src/talerconfig.test.ts
 | 
4
++--
M
packages/taler-util/src/talerconfig.ts
 | 
38
+++++++++++++++++++++++++++++++++++---

2 files changed, 37 insertions(+), 5 deletions(-)
diff --git a/packages/taler-util/src/talerconfig.test.ts b/packages/taler-util/src/talerconfig.test.ts
@@ -171,7 +171,7 @@ test("a commented-out option stays a comment with CRLF line endings", (t) => {
   );
   assert.strictEqual(
     config.stringify(),
-    "[EXCHANGE]\nBASE_URL = https://real/\n\n",
+    "[exchange]\nBASE_URL = https://real/\n\n",
   );
 });
 
@@ -204,7 +204,7 @@ test("% introduces a comment, as in the C implementation", (t) => {
   );
   assert.strictEqual(
     config.stringify(),
-    "[EXCHANGE]\nBASE_URL = https://real/\n\n",
+    "[exchange]\nBASE_URL = https://real/\n\n",
   );
 });
 
diff --git a/packages/taler-util/src/talerconfig.ts b/packages/taler-util/src/talerconfig.ts
@@ -61,6 +61,11 @@ enum EntryOrigin {
 }
 
 interface Entry {
+  /**
+   * Option name as it was first written.  Lookups are case insensitive, but
+   * write-back overwrites the user's own file and must not respell it.
+   */
+  name: string;
   value: string;
   sourceLine: number;
   sourceFile: string;
@@ -68,6 +73,10 @@ interface Entry {
 }
 
 interface Section {
+  /**
+   * Section name as it was first written; see Entry.name.
+   */
+  name: string;
   secretFilename?: string;
   inaccessible: boolean;
   entries: { [optionName: string]: Entry };
@@ -398,6 +407,22 @@ function compareFilenames(a: string, b: string): number {
   return ba.length - bb.length;
 }
 
+/**
+ * Render a value so that reading it back yields the same string.
+ *
+ * A newline would otherwise emit further configuration lines, which is how a
+ * value turns into an option the author never wrote; the C rewrites it to a
+ * literal backslash-n.  Leading and trailing whitespace only survives inside
+ * quotes, which the reader strips again.
+ */
+function serializeValue(value: string): string {
+  const escaped = value.replace(/\n/g, "\\n").replace(/\r/g, "\\r");
+  if (escaped !== escaped.trim() || /^".*"$/.test(escaped)) {
+    return `"${escaped}"`;
+  }
+  return escaped;
+}
+
 export class Configuration {
   private sectionMap: SectionMap = {};
 
@@ -619,7 +644,8 @@ export class Configuration {
           `invalid configuration, expected section header in ${fn}:${lineNo}`,
         );
       }
-      currentSection = currentSection.toUpperCase();
+      // Kept as written: provideSection() upper-cases for the lookup key, and
+      // the original spelling is what write-back emits.
       const paramMatch = line.match(reParam);
       if (paramMatch) {
         const optName = paramMatch[1].toUpperCase();
@@ -629,6 +655,7 @@ export class Configuration {
         }
         const sec = this.provideSection(currentSection);
         sec.entries[optName] = {
+          name: paramMatch[1],
           value: val,
           sourceFile: opts.filename ?? "<unknown>",
           sourceLine: lineNo,
@@ -650,6 +677,7 @@ export class Configuration {
       return this.sectionMap[secNorm];
     }
     const newSec: Section = {
+      name: section,
       entries: {},
       inaccessible: false,
     };
@@ -679,6 +707,7 @@ export class Configuration {
   setString(section: string, option: string, value: string): void {
     const sec = this.provideSection(section);
     sec.entries[option.toUpperCase()] = {
+      name: option,
       value,
       sourceLine: 0,
       sourceFile: "<unknown>",
@@ -696,6 +725,7 @@ export class Configuration {
   ): void {
     const sec = this.provideSection(section);
     sec.entries[option.toUpperCase()] = {
+      name: option,
       value,
       sourceLine: 0,
       sourceFile: "<unknown>",
@@ -949,6 +979,8 @@ export class Configuration {
     }
     for (const sectionName of Object.keys(this.sectionMap)) {
       const sec = this.sectionMap[sectionName];
+      // Names are written the way the author spelled them, not upper-cased;
+      // write() overwrites the entry point config file in place.
       let headerWritten = false;
       for (const optionName of Object.keys(sec.entries)) {
         const entry = this.sectionMap[sectionName].entries[optionName];
@@ -964,7 +996,7 @@ export class Configuration {
             s += `# Secret section from ${sec.secretFilename}\n`;
             s += `# Secret accessible: ${!sec.inaccessible}\n`;
           }
-          s += `[${sectionName}]\n`;
+          s += `[${sec.name}]\n`;
           headerWritten = true;
         }
         if (entry !== undefined) {
@@ -980,7 +1012,7 @@ export class Configuration {
                 break;
             }
           }
-          s += `${optionName} = ${entry.value}\n`;
+          s += `${entry.name} = ${serializeValue(entry.value)}\n`;
         }
       }
       if (headerWritten) {