Merge pull request #8 from hildjj/grammar-location

Grammar location
peggyjs · Dec 3, 2023 · d698cba · d698cba
2 parents 27b5253 + 41692d3
commit d698cba
Show file tree

Hide file tree

Showing 5 changed files with 349 additions and 2,153 deletions.
diff --git a/.github/workflows/node.js.yml b/.github/workflows/node.js.yml
@@ -3,34 +3,34 @@ name: Tests
 on:
   push:
     branches:
-      - '*'
+      - 'main'
   pull_request:
-    branches: ['*']
+    branches: ['main']
 
 jobs:
   build:
 
     strategy:
       matrix:
-        node-version: [18.x]
-        os: [ubuntu-latest, windows-latest, macos-latest]
+        node-version: [18.x, 20.x, 21.x]
+        os: [ubuntu-latest]
 
     runs-on: ${{ matrix.os }}
 
     steps:
-      - uses: actions/checkout@v3
+      - uses: actions/checkout@v4
       - name: Use Node.js ${{ matrix.node-version }}
-        uses: actions/setup-node@v3
+        uses: actions/setup-node@v4
         with:
           node-version: ${{ matrix.node-version }}
           cache: npm
       - name: Install dependencies
         run: npm install
       - name: Check coding standards
-        if: matrix.node-version == '18.x' && matrix.os == 'ubuntu-latest'
+        if: matrix.node-version == '21.x' && matrix.os == 'ubuntu-latest'
         run: npm run lint
       - name: Static analysis - check types
-        if: matrix.node-version == '18.x' && matrix.os == 'ubuntu-latest'
+        if: matrix.node-version == '21.x' && matrix.os == 'ubuntu-latest'
         run: npm run ts
       - name: Test
         run: npm run coverage

diff --git a/lib/index.js b/lib/index.js
@@ -1,4 +1,36 @@
 import peggy from "peggy";
+import url from "node:url";
+
+/**
+ *
+ * @param {number} depth How deep in the callstack to go?  "2" is usually the
+ *   first interesting one.
+ * @returns {peggy.GrammarLocation?} Location of the grammar in the enclosing
+ *   file.
+ */
+function callLocation(depth) {
+  const old = Error.prepareStackTrace;
+  Error.prepareStackTrace = (_, s) => s;
+  const stack = new Error().stack;
+  Error.prepareStackTrace = old;
+
+  // Not v8, or short-stacked vs. expectations
+  if (!Array.isArray(stack) || (stack.length < depth)) {
+    return null;
+  }
+
+  const callsite = stack[depth];
+  const source = callsite.getFileName();
+  const path = source.startsWith("file:") ? url.fileURLToPath(source) : source;
+  return new peggy.GrammarLocation(
+    path,
+    {
+      offset: callsite.getPosition() + 1, // Go past backtick
+      line: callsite.getLineNumber(),
+      column: callsite.getColumnNumber() + 1,  // Go past backtick
+    }
+  );
+}
 
 /**
  * Turn a templated string into a Peggy parsing function.
@@ -13,9 +45,10 @@ function pegWithOptions(opts, strings, ...values) {
   strings.forEach((string, i) => {
     text += string + (values[i] || "");
   });
+  const grammarSource = callLocation(3) || "peggy-tag";
   try {
     const parser = peggy.generate(text, {
-      grammarSource: "peggy-tag",
+      grammarSource,
       ...opts,
     }).parse;
     return (text, options = {}) => {
@@ -37,7 +70,7 @@ function pegWithOptions(opts, strings, ...values) {
     // @ts-ignore
     if (typeof e?.format === "function") {
       // @ts-ignore
-      e.message = e.format([{ source: "peggy-tag", text }]);
+      e.message = e.format([{ source: grammarSource, text }]);
     }
     throw e;
   }