1 files changed, 41 insertions, 0 deletions
diff --git a/packages/sol-trace-based-tools-common/src/collect_coverage_entries.ts b/packages/sol-trace-based-tools-common/src/collect_coverage_entries.ts
new file mode 100644
index 000000000..bdbcd613e
--- /dev/null
+++ b/packages/sol-trace-based-tools-common/src/collect_coverage_entries.ts
@@ -0,0 +1,41 @@
+import * as ethUtil from 'ethereumjs-util';
+import * as _ from 'lodash';
+import * as parser from 'solidity-parser-antlr';
+
+import { ASTVisitor, CoverageEntriesDescription } from './ast_visitor';
+import { getLocationByOffset } from './source_maps';
+
+const IGNORE_RE = /\/\*\s*solcov\s+ignore\s+next\s*\*\/\s*/gm;
+
+// Parsing source code for each transaction/code is slow and therefore we cache it
+const coverageEntriesBySourceHash: { [sourceHash: string]: CoverageEntriesDescription } = {};
+
+export const collectCoverageEntries = (contractSource: string) => {
+    const sourceHash = ethUtil.sha3(contractSource).toString('hex');
+    if (_.isUndefined(coverageEntriesBySourceHash[sourceHash]) && !_.isUndefined(contractSource)) {
+        const ast = parser.parse(contractSource, { range: true });
+        const locationByOffset = getLocationByOffset(contractSource);
+        const ignoreRangesBegingingAt = gatherRangesToIgnore(contractSource);
+        const visitor = new ASTVisitor(locationByOffset, ignoreRangesBegingingAt);
+        parser.visit(ast, visitor);
+        coverageEntriesBySourceHash[sourceHash] = visitor.getCollectedCoverageEntries();
+    }
+    const coverageEntriesDescription = coverageEntriesBySourceHash[sourceHash];
+    return coverageEntriesDescription;
+};
+
+// Gather the start index of all code blocks preceeded by "/* solcov ignore next */"
+function gatherRangesToIgnore(contractSource: string): number[] {
+    const ignoreRangesStart = [];
+
+    let match;
+    do {
+        match = IGNORE_RE.exec(contractSource);
+        if (match) {
+            const matchLen = match[0].length;
+            ignoreRangesStart.push(match.index + matchLen);
+        }
+    } while (match);
+
+    return ignoreRangesStart;
+}